8+ Solving Two-Step Word Problems (+ & -)


8+ Solving Two-Step Word Problems (+ & -)

These mathematical challenges contain discovering options by combining addition and subtraction operations in a particular sequence. For example, a situation may current a beginning amount, adopted by a rise after which a lower, requiring two separate calculations to reach on the closing reply. The sort of downside usually includes real-world contexts, like calculating the remaining price range after buying gadgets and receiving a refund.

Growing proficiency in these sequential operations builds a vital basis for extra advanced mathematical reasoning. The flexibility to dissect multi-step issues and apply the right operations so as fosters important pondering and problem-solving expertise relevant throughout numerous disciplines. Traditionally, the event of such arithmetic expertise has been important for developments in commerce, science, and engineering, demonstrating the long-standing sensible worth of this sort of mathematical literacy.

This text will additional discover methods for fixing all these issues, providing sensible examples and methods to enhance comprehension and accuracy. Particular areas of focus will embody figuring out key phrases that sign the mandatory operations, visualizing the issue by means of diagrams or fashions, and checking the reasonableness of options.

1. Sequential Operations

Sequential operations type the core of two-step addition and subtraction phrase issues. Understanding the order through which these operations are carried out is essential for arriving on the right answer. This part explores the aspects of sequential operations inside this context.

  • Order of Operations

    The order of operations dictates which calculation ought to be carried out first. In two-step issues, this usually includes figuring out whether or not addition or subtraction precedes the opposite. Misinterpreting the order can result in incorrect outcomes. For instance, if an issue includes incomes cash after which spending some, the addition (incomes) should precede the subtraction (spending) to precisely mirror the ultimate quantity.

  • Affect on the Ultimate End result

    The sequence of operations instantly impacts the ultimate outcome. Altering the order alters the intermediate values and, consequently, the answer. Think about a situation involving including a sure amount after which subtracting a unique amount. Reversing these operations will usually produce a unique final result. The particular numerical values concerned decide the magnitude of this distinction.

  • Actual-World Functions

    Sequential operations ceaselessly seem in on a regular basis situations. Managing funds, calculating distances traveled, or figuring out stock ranges usually contain a number of steps of addition and subtraction carried out in a particular order. Recognizing these sequential operations inside real-world contexts strengthens sensible mathematical utility expertise.

  • Relationship to Drawback Decomposition

    Fixing two-step issues depends on decomposing the issue into particular person steps. This decomposition aligns with the idea of sequential operations, as every decomposed step usually corresponds to a particular addition or subtraction operation. The flexibility to interrupt down a posh downside into smaller, sequential steps is essential for profitable problem-solving.

Mastering sequential operations is crucial for efficiently navigating two-step addition and subtraction phrase issues. Recognizing the order of operations, understanding its affect on the ultimate outcome, and making use of these ideas to real-world situations strengthens mathematical reasoning and problem-solving talents. This understanding supplies a basis for tackling extra advanced mathematical challenges.

2. Actual-world Contexts

Actual-world contexts present sensible which means and relevance to two-step addition and subtraction phrase issues. Connecting summary mathematical ideas to tangible situations enhances comprehension and demonstrates the sensible utility of those operations. This connection fosters deeper understanding and motivates learners by illustrating the applicability of arithmetic to on a regular basis conditions. For instance, calculating the whole value of groceries after making use of coupons or figuring out the remaining steadiness on a present card after a number of purchases exemplifies the direct relevance of those mathematical expertise.

Using real-world contexts facilitates the event of problem-solving expertise relevant past the classroom. Analyzing situations involving cash, distance, time, or portions reinforces the flexibility to extract related info, formulate equations, and interpret options inside a sensible framework. Think about calculating the whole distance traveled on a street journey with a number of legs or figuring out the online change in temperature after a sequence of will increase and reduces. These examples display the transferability of those mathematical expertise to numerous conditions.

Embedding two-step addition and subtraction issues inside real-world contexts bridges the hole between summary ideas and sensible purposes. This method strengthens mathematical literacy, enabling people to navigate on a regular basis conditions requiring quantitative reasoning successfully. The flexibility to research, interpret, and remedy issues grounded in real-world situations empowers knowledgeable decision-making and promotes a deeper appreciation for the sensible worth of arithmetic.

3. Drawback Decomposition

Drawback decomposition performs a vital position in fixing two-step addition and subtraction phrase issues. It includes breaking down advanced issues into smaller, extra manageable elements. This simplifies the method by permitting give attention to particular person elements earlier than combining them to reach on the closing answer. The lack to decompose an issue can result in confusion and errors, particularly when coping with a number of operations and portions. For example, think about a situation involving buying a number of gadgets at totally different costs after which making use of a reduction. Decomposing this downside would contain calculating the preliminary whole value, then calculating the low cost quantity, and eventually subtracting the low cost from the whole value. With out decomposition, managing these particular person steps turns into considerably more difficult.

The significance of downside decomposition extends past merely organizing the steps concerned. It fosters a deeper understanding of the issue’s construction and the relationships between totally different portions. By isolating every step, one can analyze the knowledge offered, establish the related operations, and decide the suitable sequence of calculations. This methodical method reduces cognitive load and facilitates correct answer improvement. Moreover, downside decomposition promotes the event of transferable problem-solving expertise relevant to a wider vary of mathematical and real-world challenges. For instance, calculating the whole earnings from a number of sources of earnings after which deducting bills may be effectively addressed by means of correct decomposition.

In abstract, downside decomposition serves as a cornerstone for successfully tackling two-step addition and subtraction phrase issues. This methodical method enhances comprehension, reduces errors, and promotes the event of sturdy problem-solving expertise relevant past the particular context of those issues. The flexibility to decompose advanced issues into manageable elements empowers people to confidently method a wider vary of mathematical and real-world challenges. Failure to develop this talent can hinder one’s means to successfully analyze, interpret, and remedy advanced quantitative issues.

4. Important Pondering

Important pondering performs a significant position in fixing two-step addition and subtraction phrase issues. It goes past merely performing calculations; it includes analyzing the issue, figuring out related info, and formulating a strategic method. Important pondering allows people to navigate the complexities of those issues, avoiding frequent pitfalls and guaranteeing correct options. With out important pondering, one might misread info, apply incorrect operations, or overlook essential particulars, finally resulting in faulty conclusions. This part explores the multifaceted connection between important pondering and these mathematical challenges.

  • Data Evaluation

    Important pondering requires cautious evaluation of the knowledge offered in the issue. This contains figuring out key portions, understanding the relationships between them, and discerning related info from extraneous particulars. For example, an issue may describe a situation involving shopping for, promoting, and donating gadgets. Important pondering helps decide which portions contribute to the ultimate reply and that are irrelevant. Correct info evaluation types the idea for subsequent steps within the problem-solving course of.

  • Strategic Method Formulation

    Growing a strategic method is essential for tackling two-step issues successfully. Important pondering allows people to find out the suitable sequence of operations, contemplating the relationships between totally different portions. For instance, if an issue includes incomes cash after which spending some, important pondering dictates that addition (incomes) should precede subtraction (spending) to mirror the monetary state of affairs precisely. A well-defined technique optimizes the answer course of and minimizes errors.

  • Resolution Interpretation and Validation

    Important pondering extends past calculating a numerical reply; it includes decoding the answer inside the context of the issue. This contains evaluating the reasonableness of the reply and checking for consistency with the given info. For instance, if an issue asks for the remaining amount of cash after a number of transactions, a destructive reply may point out an error within the calculations or an overspending situation. Important pondering helps validate the answer and guarantee it aligns with the issue’s parameters. Think about a situation the place the ultimate reply represents the variety of apples remaining. A fractional reply could be illogical, prompting a assessment of the answer course of.

  • Transferable Ability Growth

    Growing important pondering expertise by means of two-step phrase issues has broader implications past arithmetic. These expertise, together with info evaluation, strategic planning, and answer validation, are transferable to varied tutorial disciplines and real-world conditions. The flexibility to critically analyze info, formulate efficient methods, and consider options are important belongings in decision-making, problem-solving, and navigating advanced situations throughout numerous contexts.

Important pondering types an integral a part of efficiently fixing two-step addition and subtraction phrase issues. It empowers people to method these challenges strategically, guaranteeing correct options and growing invaluable transferable expertise. By emphasizing info evaluation, strategic method formulation, answer interpretation, and recognizing the broader applicability of those expertise, important pondering cultivates sturdy problem-solving talents important for navigating tutorial and real-world complexities.

5. Order of Operations

The order of operations, usually remembered by the acronym PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction), governs the sequence through which calculations are carried out. Inside two-step addition and subtraction phrase issues, understanding and making use of the order of operations is essential for arriving on the right answer. Whereas these issues might not contain parentheses or exponents, the order through which addition and subtraction are carried out considerably impacts the result. This part explores the aspects of the order of operations inside the context of those phrase issues.

  • Sequential Processing

    Two-step phrase issues inherently contain sequential processing, the place one operation follows one other. The order of operations dictates which calculation happens first. For example, in an issue involving incomes cash after which spending some, addition (incomes) should precede subtraction (spending) to mirror the ultimate quantity precisely. Ignoring this sequence results in incorrect outcomes, highlighting the significance of understanding sequential processing inside the order of operations.

  • Addition and Subtraction Hierarchy

    Whereas addition and subtraction maintain the identical priority inside the order of operations, they’re carried out from left to proper once they seem consecutively in an issue. This left-to-right rule ensures consistency and prevents ambiguity. For instance, in an issue involving including a worth after which subtracting one other, the addition is carried out earlier than the subtraction, whatever the numerical values concerned. This reinforces the structured method required by the order of operations.

  • Affect on Intermediate Values

    The order of operations instantly impacts the intermediate values calculated inside a two-step downside. These intermediate values, the outcomes of the primary operation, function enter for the second operation. Consequently, altering the order of operations modifications the intermediate values and, due to this fact, the ultimate answer. Think about calculating the whole value of a number of gadgets after which deducting a reduction. The order of calculation considerably impacts the ultimate value.

  • Basis for Complicated Issues

    Mastering the order of operations inside two-step issues supplies a strong basis for tackling extra advanced mathematical challenges involving a number of operations, parentheses, and exponents. The ideas of sequential processing and hierarchical execution established in these easier issues lengthen to extra superior mathematical ideas. This elementary understanding turns into important for future mathematical studying and problem-solving.

A radical understanding of the order of operations is indispensable for precisely fixing two-step addition and subtraction phrase issues. Making use of the ideas of sequential processing and respecting the addition/subtraction hierarchy ensures right calculation and interpretation of intermediate values, resulting in correct closing options. This foundational understanding additionally prepares people for extra advanced mathematical ideas and problem-solving situations.

6. Key phrase Identification

Key phrase identification performs a vital position in accurately decoding and fixing two-step addition and subtraction phrase issues. These key phrases act as indicators, indicating which operations to carry out and the relationships between totally different portions inside the issue. Correct key phrase identification is crucial for translating the narrative of a phrase downside right into a mathematical expression. Failure to establish key phrases accurately can result in misinterpretation of the issue and finally, an incorrect answer.

  • Addition Key phrases

    Sure key phrases sometimes point out addition. Phrases like “sum,” “whole,” “in all,” “mixed,” “greater than,” and “elevated by” recommend that portions are being mixed. For example, in an issue stating, “John has 5 apples and receives 3 extra,” the key phrase “extra” indicators addition. Recognizing these key phrases is essential for figuring out the suitable operation and organising the issue accurately.

  • Subtraction Key phrases

    Different key phrases sign subtraction. Phrases like “distinction,” “lower than,” “decreased by,” “fewer,” “stay,” and “take away” recommend a discount in amount. For instance, in an issue stating, “Sarah had 10 {dollars} and spent 4,” the key phrase “spent” signifies subtraction. Precisely figuring out these key phrases prevents misinterpretation and guides the correct setup of the subtraction operation.

  • Key phrases Indicating Sequential Operations

    Some key phrases make clear the sequence of operations. Phrases like “then,” “after,” and “adopted by” point out that one motion happens after one other, establishing the order of addition and subtraction. For instance, an issue stating, “A retailer had 20 gadgets, offered 5, after which obtained 12 extra,” the key phrase “then” indicators the order of subtraction (promoting) adopted by addition (receiving). Understanding these sequential key phrases is essential for accurately structuring the two-step calculation.

  • Contextual Nuances

    Whereas key phrases usually present robust clues, it is necessary to contemplate the context of your complete downside. Some phrases might need a number of interpretations relying on their utilization. Important pondering and cautious evaluation of the issue’s narrative are essential to keep away from misinterpretations primarily based solely on remoted key phrases. For instance, the phrase “left” might point out subtraction in a single context (e.g., “5 apples had been eaten, 3 had been left”) and point out no operation in one other (e.g., “He left the shop with 5 apples”). This reinforces the significance of mixing key phrase identification with complete downside evaluation.

Efficient key phrase identification supplies a important hyperlink between the textual illustration of a two-step addition and subtraction phrase downside and its mathematical formulation. By recognizing key phrases related to addition, subtraction, and sequential operations, and by contemplating contextual nuances, people can precisely translate the issue’s narrative right into a sequence of mathematical steps, paving the way in which for an accurate answer. Mastering this talent considerably enhances comprehension and problem-solving proficiency on this important space of arithmetic.

7. Resolution Verification

Resolution verification constitutes a vital closing step in fixing two-step addition and subtraction phrase issues. It strikes past merely arriving at a numerical reply; it includes critically evaluating the answer’s reasonableness and accuracy inside the context of the issue. Verification ensures the answer aligns with the issue’s parameters and displays a real understanding of the underlying mathematical ideas. Neglecting answer verification will increase the chance of accepting incorrect solutions, hindering the event of sturdy problem-solving expertise.

  • Reasonableness Checks

    Reasonableness checks contain assessing whether or not the answer is smart inside the real-world context of the issue. For example, if an issue asks for the remaining amount of cash after a sequence of transactions, a destructive reply may sign a computational error or an overspending situation. Equally, if an issue includes calculating the variety of gadgets remaining, a fractional or destructive reply could be illogical. Reasonableness checks present a fast preliminary evaluation of the answer’s validity.

  • Reverse Operations

    Using reverse operations affords a extra rigorous methodology of answer verification. By working backward from the answer utilizing the inverse operations, one can verify if the preliminary situations of the issue are glad. For instance, in a two-step downside involving addition adopted by subtraction, verification would contain including the subtracted worth again to the answer after which subtracting the added worth. If the outcome matches the preliminary amount given in the issue, the answer is probably going right.

  • Estimation Methods

    Estimation methods present a invaluable instrument for verifying options, particularly when coping with bigger numbers or extra advanced situations. By rounding the numbers concerned in the issue and performing fast psychological calculations, one can acquire an approximate answer. Evaluating this estimate with the calculated answer permits for a fast verify of the answer’s magnitude and helps establish potential errors. That is significantly helpful when exact calculations will not be required, and a basic concept of the answer’s vary suffices.

  • Various Resolution Strategies

    When relevant, using various answer strategies can strengthen answer verification. If the identical answer is obtained by means of totally different approaches, the arrogance in its accuracy will increase considerably. For example, a two-step downside can generally be solved by combining the 2 steps right into a single equal operation or by altering the order of operations whereas sustaining mathematical equivalence. If each strategies yield the identical outcome, it reinforces the answer’s validity.

Resolution verification is an integral element of the problem-solving course of for two-step addition and subtraction phrase issues. By using reasonableness checks, reverse operations, estimation methods, and various answer strategies, people can construct confidence of their options and develop stronger problem-solving expertise. These verification methods not solely guarantee accuracy but additionally foster a deeper understanding of the underlying mathematical ideas and promote important pondering. Neglecting this significant step undermines the educational course of and will increase the probability of accepting faulty outcomes.

8. Mathematical Literacy

Mathematical literacy encompasses the capability to cause mathematically and apply mathematical ideas, procedures, details, and instruments to explain, clarify, and predict phenomena. It empowers people to acknowledge the position arithmetic performs on this planet and make well-founded judgments and choices wanted for productive and engaged citizenship. Two-step addition and subtraction phrase issues function a foundational component in growing this significant literacy, offering a sensible context for making use of elementary mathematical operations and fostering analytical expertise.

  • Drawback-Fixing and Reasoning

    Two-step phrase issues necessitate using problem-solving methods and logical reasoning. Deconstructing the issue, figuring out related info, and deciding on applicable operations require analytical pondering. These issues problem people to maneuver past rote memorization and apply mathematical ideas to unravel real-world situations. Examples embody figuring out the remaining steadiness after a number of monetary transactions or calculating the whole distance traveled with a number of legs of a journey. These experiences domesticate important problem-solving expertise relevant in numerous facets of life.

  • Illustration and Interpretation

    Mathematical literacy includes understanding and using numerous representations of mathematical info. Two-step phrase issues current info narratively, requiring people to translate this narrative into mathematical expressions. This translation course of strengthens the flexibility to interpret and signify quantitative info in several codecs. For example, changing a phrase downside about combining and evaluating portions right into a numerical expression demonstrates this talent. This means is key for understanding knowledge offered in tables, graphs, and equations encountered in on a regular basis life.

  • Communication and Argumentation

    Mathematical literacy extends to successfully speaking mathematical concepts and justifying options. Two-step phrase issues present alternatives to elucidate the reasoning behind the chosen operations and the logic resulting in the answer. Articulating the steps taken to unravel an issue enhances communication expertise and fosters the flexibility to assemble logical arguments. For instance, explaining why addition precedes subtraction in a specific downside strengthens mathematical communication. This talent turns into essential for successfully conveying quantitative info and defending conclusions primarily based on mathematical reasoning in numerous skilled and private settings.

  • Connecting and Making use of Arithmetic

    Two-step phrase issues spotlight the sensible purposes of arithmetic in on a regular basis situations. By contextualizing mathematical operations inside real-world conditions, these issues display the relevance of arithmetic past summary ideas. This connection fosters a deeper appreciation for the utility of arithmetic and motivates additional exploration of its purposes. Examples akin to calculating the whole value of groceries after reductions or figuring out the time required to finish a job with a number of steps underscore the sensible worth of mathematical expertise. This understanding encourages people to view arithmetic as a sensible instrument for navigating and decoding the world round them.

Proficiency in fixing two-step addition and subtraction phrase issues contributes considerably to the event of broader mathematical literacy. By fostering problem-solving expertise, enhancing representational fluency, bettering mathematical communication, and demonstrating the sensible purposes of arithmetic, these issues set up a strong basis for future mathematical studying and empower people to have interaction confidently with quantitative info in numerous contexts. This basis is crucial for knowledgeable decision-making, efficient problem-solving, and energetic participation in a society more and more reliant on quantitative knowledge and evaluation.

Ceaselessly Requested Questions

This part addresses frequent queries relating to two-step addition and subtraction phrase issues, offering readability on potential areas of confusion and reinforcing key ideas.

Query 1: What distinguishes a two-step phrase downside from a one-step downside?

One-step issues require a single operation (addition or subtraction) to reach on the answer. Two-step issues, nonetheless, necessitate two sequential operations, usually combining addition and subtraction, to achieve the ultimate reply. This sequential nature will increase the complexity and requires a extra structured method.

Query 2: How does one decide the right order of operations in these issues?

The order of operations, whereas essential, is usually implicitly outlined inside the issue’s narrative. Cautious evaluation of the issue’s wording, specializing in key phrases like “then,” “after,” or “adopted by,” reveals the sequence of actions and, consequently, the order of operations. Moreover, understanding the context of the issue helps make clear the logical sequence of occasions and the corresponding mathematical operations.

Query 3: What are frequent key phrases that point out addition or subtraction?

Key phrases akin to “sum,” “whole,” “in all,” “mixed,” and “greater than” sometimes sign addition. Key phrases like “distinction,” “lower than,” “decreased by,” “fewer,” and “stay” usually point out subtraction. Nonetheless, relying solely on key phrases may be deceptive; cautious consideration of the issue’s general context is essential for correct interpretation.

Query 4: How can one confirm the answer to a two-step phrase downside?

Resolution verification can contain a number of methods. Checking the reasonableness of the reply inside the issue’s context is a vital first step. Using reverse operations, working backward from the answer to see if it aligns with the preliminary situations, supplies additional validation. Estimation methods, utilizing rounded values for fast psychological calculations, provide a preliminary verify of the answer’s magnitude.

Query 5: Why are all these issues necessary for growing mathematical literacy?

Two-step addition and subtraction phrase issues contribute considerably to mathematical literacy by fostering important pondering, problem-solving expertise, and the flexibility to translate real-world situations into mathematical expressions. They supply a sensible context for making use of mathematical operations and decoding quantitative info, expertise important for navigating on a regular basis conditions and extra superior mathematical ideas.

Query 6: What are some frequent challenges encountered when fixing these issues, and the way can they be addressed?

Frequent challenges embody misinterpreting the issue’s narrative, incorrectly figuring out the order of operations, and neglecting to confirm the answer. Addressing these challenges includes cautious studying and evaluation of the issue, paying shut consideration to key phrases and the general context, and adopting a scientific method to downside decomposition and answer verification. Common observe and targeted consideration to those areas considerably enhance proficiency.

Understanding these frequent queries strengthens one’s means to method two-step addition and subtraction phrase issues strategically, selling accuracy and deeper comprehension of the underlying mathematical ideas.

This text will additional delve into particular examples and supply sensible methods for mastering these important mathematical issues.

Ideas for Fixing Two-Step Addition and Subtraction Phrase Issues

The following tips provide sensible methods to reinforce comprehension and accuracy when addressing these mathematical challenges. Cautious utility of those methods promotes a scientific method and strengthens problem-solving expertise.

Tip 1: Learn Rigorously and Visualize:

Thorough studying and visualization are paramount. One ought to fastidiously learn the issue a number of occasions, visualizing the situation to know the relationships between portions. Making a psychological picture or a easy sketch can considerably support in understanding the issue’s construction. For instance, when offered with an issue involving the motion of objects, visualizing the objects and their actions clarifies the operations wanted.

Tip 2: Establish Key phrases:

Figuring out key phrases supplies essential clues concerning the operations concerned. Phrases like “sum,” “whole,” “extra,” “distinction,” “much less,” and “stay” sign particular mathematical actions. Nonetheless, contextual understanding is important, as the identical key phrase can have totally different interpretations primarily based on the issue’s narrative.

Tip 3: Decompose the Drawback:

Breaking down advanced issues into smaller, manageable steps simplifies the answer course of. Concentrate on one step at a time, performing the mandatory calculations earlier than shifting on to the following. This structured method prevents errors and promotes readability.

Tip 4: Decide the Order of Operations:

The sequence of operations dramatically impacts the ultimate outcome. Rigorously analyze the issue to find out whether or not addition or subtraction ought to be carried out first. Think about the chronological order of occasions described in the issue and any key phrases that recommend a particular sequence.

Tip 5: Write the Mathematical Expression:

Translate the issue’s narrative right into a mathematical expression utilizing numbers and symbols. This supplies a transparent, concise illustration of the issue and guides the calculations. Double-check the expression to make sure it precisely displays the issue’s info.

Tip 6: Carry out the Calculations:

Execute the calculations in line with the established order of operations. Double-check every calculation for accuracy. Easy errors can considerably have an effect on the ultimate outcome, significantly in multi-step issues.

Tip 7: Confirm the Resolution:

After acquiring an answer, critically consider its reasonableness. Does the reply make sense inside the issue’s context? Using reverse operations or estimation methods might help affirm the answer’s accuracy. Think about whether or not the answer aligns with the real-world situation offered in the issue.

Constant utility of the following tips fosters a methodical method, enhancing comprehension, accuracy, and problem-solving proficiency. These expertise lengthen past these particular issues, offering a strong basis for tackling extra advanced mathematical challenges.

This exploration of sensible suggestions transitions to the article’s conclusion, summarizing key takeaways and emphasizing the significance of mastering these elementary mathematical expertise.

Conclusion

This exploration of two-step addition and subtraction phrase issues has highlighted their significance in growing elementary mathematical literacy. The evaluation encompassed key facets, together with sequential operations, real-world contexts, downside decomposition, important pondering, the order of operations, key phrase identification, answer verification, and the broader implications for mathematical literacy. Understanding these elements is essential for precisely decoding, fixing, and verifying options to those issues. The dialogue emphasised the significance of a scientific method, combining cautious studying, strategic decomposition, and rigorous verification to make sure accuracy and foster deeper comprehension.

Mastery of those foundational mathematical expertise extends past the particular context of two-step addition and subtraction phrase issues. These expertise domesticate important pondering, analytical reasoning, and problem-solving talents relevant to a variety of educational disciplines and real-world situations. The flexibility to successfully analyze info, formulate methods, and consider options represents a necessary asset for navigating the complexities of an more and more quantitative world. Continued emphasis on these elementary expertise will empower people to have interaction confidently with mathematical ideas and contribute meaningfully to knowledgeable decision-making.