All questions
Question 1
A student writes the expression 18−(6+4). What is the value of the expression 18−(6+4)?
- 8 (correct answer)
- 16
- 10
- 4
Explanation: Grouping symbols like parentheses affect the order of operations in an expression by specifying which calculations to perform first. To evaluate an expression with grouping symbols, you must start by solving the operations inside the symbols before moving to the rest of the expression. This changes the result because it overrides the standard order of operations, potentially leading to a different value than if the symbols were absent. For example, in 18 - (6 + 4), you add 6 + 4 inside the parentheses to get 10, then subtract to get 8. A common misconception is that you can ignore parentheses and just go left to right, but this would incorrectly give 18 - 6 + 4 = 16. Grouping symbols are important because they ensure the expression is calculated as intended. They help avoid ambiguity in mathematical communication and real-world applications like budgeting or recipes.
Question 2
A student is packing snack bags. The total number of crackers is found by evaluating 7×[12−(5+3)]. What is the value of 7×[12−(5+3)]?
- 28 (correct answer)
- 56
- 52
- 4
Explanation: Grouping symbols such as parentheses and brackets affect the order by requiring you to work from the innermost symbols outward. You evaluate inside the innermost grouping first, then proceed to the next level. This alters the outcome by changing which numbers are combined at each step. For instance, in 7 × [12 - (5 + 3)], add 5 + 3 to 8, subtract from 12 to get 4, then multiply by 7 for 28. A misconception is that all grouping symbols are the same, but you must handle nested ones step by step. Grouping symbols are essential for complex expressions to convey intended meaning. They promote accuracy in mathematical communication and problem-solving.
Question 3
A student is comparing two ways to write a score calculation: 8×(9+3) and 8×9+3. Which statement best explains how the parentheses change the value?
- The parentheses make you add 9 and 3 first, so 8 is multiplied by the total. (correct answer)
- The parentheses mean you multiply 8 and 9 first, then add 3 at the end.
- The parentheses mean you add 8 and 9 first, then multiply by 3.
- The parentheses do not change anything because you always go left to right.
Explanation: Grouping symbols affect the order of operations by indicating which parts to compute first. You evaluate inside the parentheses first, performing the addition before the multiplication. This changes the result from 75 without parentheses to 96 with them, as the addition is grouped. For instance, 8×(9+3) becomes 8×12=96, while 8×9+3=72+3=75. One misconception is thinking parentheses always mean multiply first, but they prioritize the operation inside. Grouping symbols are crucial for specifying exact calculations in scores or other applications. They prevent ambiguity and ensure accurate results in math.
Question 4
A game uses this expression to find points: 48÷(6+2). What is the value of the expression?
- 10
- 8
- 14
- 6 (correct answer)
Explanation: Grouping symbols affect the order of operations by requiring you to handle inside them before outside. Evaluate the addition inside the parentheses first, then do the division. This changes the result to 6 instead of something like 48÷6+2=10. In this case, 48÷(6+2)=48÷8=6 for the points. A misconception is dividing before adding without respecting the symbols, leading to wrong answers. Grouping symbols are important for precise instructions in games or recipes. They make sure calculations match the intended meaning.
Question 5
A teacher compares 30−(12−4) and (30−12)−4. What is the value of 30−(12−4)?
- 14
- 22 (correct answer)
- 10
- 18
Explanation: Grouping symbols like parentheses affect the order in which we perform operations in an expression. We always evaluate the operations inside the grouping symbols first before doing anything outside them. This changes the result by altering which subtraction happens first, making 30 - (12 - 4) equal to 22, while (30 - 12) - 4 equals 14. For example, in 30 - (12 - 4), we subtract inside to get 8, then 30 - 8 = 22. A common misconception is that all subtractions are done left to right regardless of parentheses, but parentheses must be resolved first. Grouping symbols are important because they prevent misinterpretation of expressions. They ensure accuracy in comparisons, like in teaching scenarios.
Question 6
Two students compare expressions. Which statement is true about the values of 9×(3+2) and 9×3+2?
- They have the same value because you multiply before you add in both.
- The first expression is greater because you add inside the parentheses first. (correct answer)
- The second expression is greater because the parentheses make the number smaller.
- They have the same value because parentheses do not change the order.
Explanation: Grouping symbols affect the order of operations by prioritizing the calculations within them over the standard rules. You must evaluate inside the parentheses first before applying other operations like multiplication. This often leads to a different result than if the expression had no grouping. In comparing 9 × (3 + 2) which is 45 and 9 × 3 + 2 which is 29, the parentheses make the first greater by adding before multiplying. A misconception is that parentheses don't change the value, but they do by altering the sequence. Grouping symbols are important for expressing specific mathematical ideas clearly. They ensure consistency and prevent misinterpretation in equations.
Question 7
Two expressions use the same numbers but different grouping. Which statement correctly compares 20−(8+4) and (20−8)+4?
- They have the same value because subtraction and addition can be done in any order.
- The first expression is greater because the parentheses make you subtract first.
- The second expression is greater because the grouping changes which numbers are combined first. (correct answer)
- They have the same value because parentheses do not affect the result.
Explanation: Grouping symbols affect the order of operations by determining which subtractions or additions happen first. You evaluate inside each set of parentheses separately before combining. This leads to different values, like 8 versus 16 in the two expressions. Comparing 20 - (8 + 4) = 8 and (20 - 8) + 4 = 16 shows the second is greater due to grouping changes. A misconception is that addition and subtraction order doesn't matter with parentheses, but it does. Grouping symbols are important for conveying exact mathematical intent. They help in distinguishing between similar-looking expressions with different meanings.
Question 8
A student evaluates 72÷8+(9−3). What is the value of the expression?
- 60
- 15 (correct answer)
- 3
- 9
Explanation: Grouping symbols like parentheses affect the order in which we perform operations in an expression. We always evaluate the operations inside the grouping symbols first before doing anything outside them. This changes the result by adding the resolved parentheses after division, leading to 9 + 6 = 15. For example, in 72 ÷ 8 + (9 - 3), we subtract to 6 inside, divide 72 by 8, then add. A common misconception is that addition comes before division, but we do division and multiplication before addition after parentheses. Grouping symbols are important because they clarify priorities in mixed operations. They help students evaluate expressions correctly.
Question 9
A teacher writes the expression 8×(6+4) on the board. What is the value of the expression 8×(6+4)?
- 80 (correct answer)
- 52
- 320
- 112
Explanation: Grouping symbols like parentheses affect the order of operations in an expression by specifying which calculations to perform first. To evaluate, you always start by solving the operations inside the grouping symbols before moving to the outside operations. This changes the result because it overrides the standard order of operations, such as multiplying before adding. For example, in 8 × (6 + 4), you add 6 + 4 inside the parentheses to get 10, then multiply by 8 to get 80. A common misconception is that you can ignore parentheses and just follow PEMDAS strictly, but parentheses must be addressed first. Grouping symbols are important because they ensure everyone interprets the expression the same way. They allow for precise control over the calculation sequence, preventing confusion in math problems.
Question 10
Two students wrote different expressions for the same numbers: 9×(10−2) and (9×10)−2. Which statement is true about how the parentheses change the value?
- Both expressions have the same value because parentheses never change the value.
- The first expression subtracts first, but the second expression multiplies first, so the values are different. (correct answer)
- The first expression multiplies first, but the second expression subtracts first, so the values are different.
- Both expressions have the same value because you always do multiplication before subtraction no matter what.
Explanation: Grouping symbols affect the order of operations by prioritizing inside them. Evaluate subtraction or multiplication inside first as grouped. This changes results, like 72 for the first and 88 for the second. For example, 9×(10-2)=9×8=72, while (9×10)-2=90-2=88. A misconception is thinking order is always multiplication first regardless of parentheses. Grouping symbols are vital for different interpretations in student work. They allow precise control over calculation sequences.
Question 11
A teacher writes two expressions on the board: 24÷(8−2) and 24÷8−2. Which statement best explains how the grouping changes the value?
- The parentheses make you subtract first, so you divide by 6 instead of dividing by 8 first. (correct answer)
- The parentheses make you divide first, so you divide 24 by 8 before subtracting 2.
- The parentheses mean you should work strictly left to right no matter what.
- The parentheses mean you should add 8 and 2 before dividing 24.
Explanation: Grouping symbols affect the order of operations by forcing certain parts of an expression to be calculated before others. You evaluate inside the grouping symbols first, performing subtraction or other operations there before division or the rest. This changes the result by altering what numbers are operated on, leading to different outcomes with and without symbols. For instance, in 24 ÷ (8 - 2), subtracting first gives 24 ÷ 6 = 4, unlike 24 ÷ 8 - 2 = 1. A misconception is that parentheses only group numbers without changing priority, but they do enforce inner operations first. Grouping symbols are important for specifying intent in math problems. They prevent misunderstandings and are essential in programming and engineering.
Question 12
A class is packing pencils. The total is found using 3×[20−(4×2)]. What is the value of the expression?
- 36 (correct answer)
- 52
- 24
- 108
Explanation: Grouping symbols affect the order of operations, handling nested ones from inside out. Evaluate the innermost parentheses first, then the brackets. This changes the result by ensuring subtraction after multiplication inside. For pencils, 3×[20−(4×2)]=3×[20−8]=3×12=36. People might mistakenly ignore nesting and do 20-4 first, but order matters. Grouping symbols are key for complex expressions in packing or building. They provide structure and avoid errors in multi-step problems. Question 13
A calculator displays the result of [20−(4×3)]+[2×(5+3)]. If the calculator follows the correct order of operations, what number appears on the screen?
- 18
- 24 (correct answer)
- 16
- 22
Explanation: Working inside out: First bracket: 4×3=12, then 20−12=8. Second bracket: 5+3=8, then 2×8=16. Finally: 8+16=24. Choice A incorrectly calculates the second bracket as 10. Choice C stops at the first bracket calculation. Choice D makes an error in the final addition. Question 14
A class is counting markers. The total is represented by [15+5]×4. What is the value of [15+5]×4?
- 35
- 80 (correct answer)
- 100
- 20
Explanation: Grouping symbols like brackets affect the order of operations by requiring evaluation inside them before external operations. You solve the addition or other operations within the brackets first, then multiply or proceed. This modifies the final value by combining numbers in a specific way. For example, in [15 + 5] × 4, add to 20 inside, then multiply by 4 to get 80. A common misconception is that you can multiply first and add later, ignoring the brackets. Grouping symbols are important because they provide structure to expressions. They allow for clear and unambiguous mathematical statements.
Question 15
A student is evaluating 40−{6×(3+2)}. Which value is the correct value of the expression 40−{6×(3+2)}?
- 10 (correct answer)
- 34
- 4
- 70
Explanation: Grouping symbols like parentheses and braces affect the order of operations by indicating nested priorities. Evaluate inside the innermost parentheses first, then proceed to multiplication within braces. This alters the result by changing the sequence, such as doing addition before multiplication. For example, in 40 - {6 × (3 + 2)}, add 3 + 2 to 5, multiply by 6 to 30, then subtract from 40 to get 10. A misconception is ignoring braces and doing multiplication first everywhere, which would give 40 - 6 × 3 + 2 = 40 - 18 + 2 = 24. Grouping symbols are essential for directing calculations correctly. They ensure consistency in interpreting expressions across education and professions.
Question 16
A student writes two expressions: 8×(5+1) and 8×5+1. Which statement best explains how the parentheses change the value?
- The parentheses make you add 5 and 1 first, so the product is larger than 8×5+1. (correct answer)
- The parentheses mean you multiply 8 and 5 first, so both expressions have the same value.
- The parentheses mean you add 8 and 5 first, then multiply by 1.
- The parentheses mean you always divide before you add, so the value gets smaller.
Explanation: Grouping symbols like parentheses affect the order in which we perform operations in an expression. We always evaluate the operations inside the grouping symbols first before doing anything outside them. This changes the result by making us add before multiplying in 8 × (5 + 1), leading to 48, whereas without parentheses in 8 × 5 + 1, we multiply first to get 41. For example, the parentheses in 8 × (5 + 1) make the product larger by grouping the addition first. A common misconception is that parentheses always mean to multiply first, but they actually prioritize whatever is inside them. Grouping symbols are important because they control the sequence of operations to avoid confusion. They allow us to express complex ideas precisely in math.
Question 17
A student is organizing books. The number of books is found using 60−{24÷(8−4)}. What is the value of 60−{24÷(8−4)}?
- 51
- 45
- 54 (correct answer)
- 12
Explanation: Grouping symbols such as braces and parentheses affect the order by nesting operations that must be resolved inward to outward. You evaluate the innermost parentheses first, then the division inside the braces, before subtracting. This sequence changes the result by prioritizing certain calculations. In 60 - {24 ÷ (8 - 4)}, subtract to 4, divide 24 by 4 to 6, then 60 - 6 = 54. One misconception is overlooking nested symbols and doing operations out of order. Grouping symbols are crucial for handling complexity in math. They ensure everyone arrives at the same answer consistently.
Question 18
A student writes [50−(12+8)]÷5. What is the value of the expression [50−(12+8)]÷5?
- 6 (correct answer)
- 2
- 30
- 10
Explanation: Grouping symbols like brackets and parentheses affect the order by prioritizing inner addition before subtraction and division. Evaluate inside the parentheses first, then subtract within brackets before dividing. This changes the result by reducing the number being divided, yielding a specific value. In [50 - (12 + 8)] ÷ 5, add 12 + 8 to 20, subtract from 50 to 30, then divide by 5 for 6. A misconception is dividing first outside the symbols, which would incorrectly alter the sequence. Grouping symbols are important for maintaining intended calculation flow. They are used to structure problems in education and practical scenarios.
Question 19
During a class fundraiser, the total money is represented by 5×(12+8). What is the value of the expression 5×(12+8)?
- 68
- 100 (correct answer)
- 60
- 28
Explanation: Grouping symbols like parentheses affect the order of operations by prioritizing the calculations within them. When evaluating, always perform the operations inside the grouping symbols first, such as addition or subtraction, before multiplying or dividing outside. This can significantly change the result, as it groups numbers differently than the default order would. In the expression 5 × (12 + 8), you add 12 + 8 to get 20, then multiply by 5 to get 100. One misconception is thinking multiplication always comes before addition regardless of parentheses, but parentheses take precedence. Grouping symbols are crucial for clarity in expressions, ensuring everyone interprets them the same way. They are widely used in fields like science and finance to convey precise calculations.
Question 20
During a game, a student calculates points using the expression 36÷(9−3). What is the value of 36÷(9−3)?
- 5
- 18
- 2
- 6 (correct answer)
Explanation: Grouping symbols like parentheses affect the order of operations by telling you to compute inside them before anything else. You evaluate the expression inside the symbols first, then use that result in the rest of the problem. This can significantly change the final value compared to doing operations without the grouping. In 36 ÷ (9 - 3), subtract 9 - 3 to get 6 inside the parentheses, then divide 36 by 6 to get 6. One misconception is thinking division always comes before subtraction regardless of parentheses, but parentheses take priority. Grouping symbols are crucial for clarity in expressions with multiple operations. They help avoid errors by guiding the exact sequence of calculations.