All questions
Question 1
A store reduces prices by multiplying them by 54. Another store reduces prices by multiplying them by 97. Both stores start with the same $45 item. Without calculating the sale prices, which store offers the better deal and why?
- The second store, because 97 is farther from 1 than 54, creating a lower price (correct answer)
- The first store, because 54 has a smaller denominator than 97
- The first store, because 54 is farther from 1 than 97, creating a lower price
- Both stores offer the same deal because both fractions are less than 1
Explanation: When you see a problem about price reductions using multiplication, you need to understand what those fractions represent. Both stores are multiplying the original price by a fraction less than 1, which creates a sale price. The key insight is that the smaller the fraction, the bigger the discount and the lower the final price.
To compare 54 and 97 without calculating, convert them to decimals or find a common denominator. Using decimals: 54=0.8 and 97≈0.778. Since 97 is smaller, multiplying by it gives a lower sale price. You can also think about distance from 1: 54 is 51 away from 1, while 97 is 92 away from 1. Since 92>51, the fraction 97 is farther from 1.
Choice A is correct because 97 is indeed farther from 1 than 54, creating the lower price. Choice B incorrectly focuses on denominator size, which doesn't determine the fraction's value. Choice C has the logic backward—it correctly identifies that being farther from 1 creates a lower price, but wrongly claims 54 is farther from 1. Choice D misses that different fractions less than 1 create different sale prices.
Remember: when comparing discounts given as multipliers, the smaller the fraction, the bigger the discount. Focus on which fraction is closer to zero, not which has the smaller denominator. Question 2
Without calculating, arrange these products in order from smallest to largest: 81×24, 87×24, and 181×24.
- 81×24, 87×24, 181×24 (correct answer)
- 87×24, 81×24, 181×24
- 181×24, 87×24, 81×24
- 81×24, 181×24, 87×24
Explanation: Since all products use the same factor (24), we compare the other factors. 81<87<181, so the products follow the same order. 81×24 is smallest because 81 is much less than 1. 87×24 is next because 87<1. 181×24 is largest because 181>1. The other choices incorrectly order the factors or misunderstand how factor size affects product size. Question 3
Maria needs to calculate 43×8 and 65×8 for her homework. Without calculating the exact products, she wants to know which product will be closer to 8. What should Maria conclude?
- 43×8 will be closer to 8 because 43 is closer to 1
- 65×8 will be closer to 8 because 65 is closer to 1 (correct answer)
- Both products will be equally close to 8 because they use the same whole number
- 43×8 will be closer to 8 because 43 is smaller than 65
Explanation: When multiplying a whole number by a fraction, the closer the fraction is to 1, the closer the product will be to the original whole number. Since 65=0.833... is closer to 1 than 43=0.75, the product 65×8 will be closer to 8. Choice A incorrectly identifies which fraction is closer to 1. Choice C ignores the effect of different fraction multipliers. Choice D confuses smaller fractions with closer-to-8 products. Question 4
A student compares the expressions 5×54 and 5×56. The factors are 5 and 54 (less than 1) in the first expression, and 5 and 56 (greater than 1) in the second. Factor size affects product size. Which statement is correct (without calculating the exact products)?
- Both products are less than 5 because both expressions use fractions.
- Both products are greater than 5 because multiplication always increases a number.
- The product of 5×54 is less than 5, and the product of 5×56 is greater than 5. (correct answer)
- The two products are equal because the first factor is 5 in both expressions.
Explanation: The size of a factor in multiplication directly affects the size of the product compared to the other factor. When you multiply a number by a factor greater than 1, the product becomes larger than that original number. Conversely, multiplying by a fraction less than 1 results in a product that is smaller than the original number. In the expressions 5 × 4/5 and 5 × 6/5, the first product is less than 5 because 4/5 < 1, while the second is greater than 5 because 6/5 > 1. A common misconception is that shared factors make products equal, but the varying fractions determine the size differences. By reasoning about factor sizes, you can compare products without calculating exact values. This approach enhances efficiency and strengthens understanding of fraction multiplication.
Question 5
A classroom poster shows the expression 9×77. The factors are 9 and 77. Since 77 is equal to 1, multiplying by it keeps the product the same size as 9. Which statement explains the size of the product compared to 9 (without calculating)?
- The product is greater than 9 because multiplication always increases a number.
- The product is less than 9 because there is a fraction in the expression.
- The product is equal to 9 because 77 equals 1. (correct answer)
- The product is greater than 9 because you add 9 and 77.
Explanation: The size of a factor in multiplication directly affects the size of the product compared to the other factor. When you multiply a number by a factor greater than 1, the product becomes larger than that original number. Conversely, multiplying by a fraction less than 1 results in a product that is smaller than the original number. In the expression 9 × 7/7, since 7/7 equals 1, the product will be equal to 9. A common misconception is that multiplying by any fraction changes the size, but when the fraction equals 1, the product remains the same. By reasoning about factor sizes, you can determine the product's relation to the factors without full computation. This technique avoids unnecessary calculations and fosters a better grasp of multiplication principles.
Question 6
A recipe uses the multiplication expression 43×12. The factors are 43 and 12. Since 43 is less than 1, multiplying by it makes the product smaller than 12. Which statement correctly compares the product to 12 without calculating the exact product?
- The product is greater than 12 because multiplication always makes numbers larger.
- The product is less than 12 because one factor, 43, is less than 1. (correct answer)
- The product is equal to 12 because the other factor is 12.
- The product is less than 12 because any fraction makes a product smaller.
Explanation: The size of the factors in a multiplication expression directly affects the size of the product. When you multiply a number by a factor greater than 1, the product becomes larger than the original number. Conversely, multiplying by a fraction less than 1 results in a product that is smaller than the original number. In the expression (43 × 12), since (43) is less than 1, the product is less than 12, making statement B the correct comparison. A common misconception is that multiplication always increases a number's size, but this is not true when multiplying by fractions less than 1. By reasoning about whether a factor is greater than, less than, or equal to 1, we can determine the product's size relative to the other factor without full computation. This method promotes efficient thinking and deeper understanding of fractional multiplication. Question 7
A student is checking an estimate for 49×10. The factors are 49 and 10. Which claim about the product is incorrect without finding the exact product?
- The product is greater than 10 because 49 is greater than 1.
- The product is less than 10 because 49 is a fraction. (correct answer)
- The product is not equal to 10 because the factor 49 is not 1.
- The product gets larger than 10 because multiplying by a number greater than 1 stretches the other factor.
Explanation: The size of a factor in multiplication directly influences the size of the product compared to the other factor. When you multiply by a number greater than 1, the product becomes larger than the original number. When you multiply by a fraction less than 1, the product becomes smaller than the original number. In the expression (49 × 10), since (49) is greater than 1, the product is greater than 10, making the claim that it's less because it's a fraction incorrect. A common misconception is that all fractions reduce the product, overlooking improper fractions that exceed 1. By comparing the fraction to 1, you can spot incorrect claims without exact calculation. This reasoning enhances estimation abilities and applies to diverse problem-solving scenarios. Question 8
A class is comparing products. Look at 52×20. The factors are 52 and 20. Which claim about the product is incorrect (do not calculate the exact product)?
- The product is less than 20 because 52 is less than 1.
- The product would be smaller than 20 because multiplying by a number less than 1 shrinks the other factor.
- The product is greater than 20 because multiplication always makes numbers bigger. (correct answer)
- The product is not equal to 20 because the factor 52 is not 1.
Explanation: The size of a factor in multiplication directly influences the size of the product compared to the other factor. When you multiply by a number greater than 1, the product becomes larger than the original number. When you multiply by a fraction less than 1, the product becomes smaller than the original number. In the expression (52 × 20), since (52) is less than 1, the product will be less than 20, making the claim that it's greater because multiplication always makes numbers bigger incorrect. A common misconception is that multiplication inherently increases size, ignoring the role of factors less than 1. By evaluating claims against this factor comparison, you can identify errors without calculating the exact product. This reasoning skill enhances critical thinking and avoids unnecessary arithmetic in problem-solving. Question 9
A student compares two expressions: 10×87 and 10×89. The factors are 10 and 87 in the first expression, and 10 and 89 in the second. Since 87 is less than 1 and 89 is greater than 1, the factor size affects the product size. Which statement is correct without calculating either product?
- Both products are greater than 10 because both expressions use multiplication.
- Both products are less than 10 because both expressions use fractions.
- The first product is less than 10, and the second product is greater than 10. (correct answer)
- The first product is greater than 10, and the second product is less than 10.
Explanation: The size of the factors in a multiplication expression directly affects the size of the product. When you multiply a number by a factor greater than 1, the product becomes larger than the original number. Conversely, multiplying by a fraction less than 1 results in a product that is smaller than the original number. In the expressions (10 × 87) and (10 × 89), the first product is less than 10 because (87 < 1), while the second is greater than 10 because (89 > 1), making statement C correct. A common misconception is that all fractions lead to smaller products, but improper fractions can actually enlarge them. Using this factor-comparison method, we can analyze multiple expressions without computing each product. It encourages efficient problem-solving and a stronger grasp of multiplication principles. Question 10
A student compares two products: Product 1 is 23×10 and Product 2 is 43×10. Each expression has two factors: a fraction and 10. Since 23 is greater than 1 and 43 is less than 1, the factor size affects each product size. Which statement is correct, without calculating either product?
- Product 1 is greater than Product 2 because multiplying 10 by a number greater than 1 makes it bigger, while multiplying by a number less than 1 makes it smaller. (correct answer)
- Product 2 is greater than Product 1 because any fraction makes the product smaller than 10.
- The two products are equal because both expressions use 10 as a factor.
- Product 2 is greater than Product 1 because multiplication works like addition, and 43 is closer to 1 than 23.
Explanation: The size of a factor in multiplication directly influences the size of the product relative to the other factor. When you multiply a number by a factor greater than 1, the product becomes larger than that original number. Conversely, multiplying by a fraction less than 1 results in a product that is smaller than the original number. In comparing (23 × 10) and (43 × 10), since (23) is greater than 1 and (43) is less than 1, the first product is greater than 10 while the second is less than 10, making the first larger. A common misconception is that all fractions make products smaller, but this depends on whether the fraction is greater or less than 1. By reasoning about factor sizes, you can compare products without performing the full calculations. This approach saves time and helps build an intuitive understanding of how fractions affect multiplication outcomes. Question 11
A coach writes the multiplication expression 52×30 for part of a training plan. The factors are 52 and 30. Since 52 is less than 1, it affects the product size. Which statement correctly describes the size of the product compared to 30, without calculating the exact product?
- The product is greater than 30 because multiplication always increases the first number.
- The product is less than 30 because one factor is less than 1, so it makes the product smaller. (correct answer)
- The product is equal to 30 because multiplying by a fraction keeps the number the same.
- The product is less than 30 because all fractions are less than 1.
Explanation: The size of a factor in multiplication directly influences the size of the product relative to the other factor. When you multiply a number by a factor greater than 1, the product becomes larger than that original number. Conversely, multiplying by a fraction less than 1 results in a product that is smaller than the original number. In the expression (52 × 30), since (52) is less than 1, the product will be less than 30. A common misconception is that all fractions are less than 1, but some improper fractions are greater than 1 and would make the product larger. By reasoning about factor sizes, you can compare the product to one of the factors without performing the full calculation. This approach saves time and helps build an intuitive understanding of how fractions affect multiplication outcomes. Question 12
A music teacher uses the multiplication expression 241×6 to describe practice time. The factors are 241 and 6. Since 241 is greater than 1, it affects the product size. Which statement correctly describes the size of the product compared to 6, without calculating the exact product?
- The product is less than 6 because mixed numbers are fractions, and fractions always make products smaller.
- The product is equal to 6 because multiplying by a number with a fraction does not change the result.
- The product is greater than 6 because one factor is greater than 1, so it makes the product larger. (correct answer)
- The product is greater than 6 because multiplication means add 241 and 6.
Explanation: The size of a factor in multiplication directly influences the size of the product relative to the other factor. When you multiply a number by a factor greater than 1, the product becomes larger than that original number. Conversely, multiplying by a fraction less than 1 results in a product that is smaller than the original number. In the expression (241 × 6), since (241) is greater than 1, the product will be greater than 6. A common misconception is that mixed numbers behave like fractions less than 1, but those greater than 1 increase the product. By reasoning about factor sizes, you can compare the product to one of the factors without performing the full calculation. This approach saves time and helps build an intuitive understanding of how fractions affect multiplication outcomes. Question 13
A classroom has the multiplication expression 121×12 for the total length of ribbon used. The factors are 121 and 12. Since 121 is greater than 1, it affects the product size. Which statement correctly describes the size of the product compared to 12, without calculating the exact product?
- The product is greater than 12 because one factor is greater than 1, so it makes the product larger. (correct answer)
- The product is less than 12 because any fraction makes the product smaller.
- The product is equal to 12 because multiplying by a mixed number does not change the size.
- The product is greater than 12 because when you multiply you should add the numbers instead.
Explanation: The size of a factor in multiplication directly influences the size of the product relative to the other factor. When you multiply a number by a factor greater than 1, the product becomes larger than that original number. Conversely, multiplying by a fraction less than 1 results in a product that is smaller than the original number. In the expression (121 × 12), since (121) is greater than 1, the product will be greater than 12. A common misconception is that mixed numbers always make products smaller, but actually, mixed numbers greater than 1 increase the size. By reasoning about factor sizes, you can compare the product to one of the factors without performing the full calculation. This approach saves time and helps build an intuitive understanding of how fractions affect multiplication outcomes. Question 14
A school store has 14 stickers in a pack, and a student buys 76 of a pack. This is modeled by 76×14. The factors are 76 and 14. Without calculating, which statement best describes the product compared to 14?
- The product will be less than 14 because 76 is less than 1, and multiplying by a number less than 1 makes the product smaller. (correct answer)
- The product will be greater than 14 because multiplication always increases the number of stickers.
- The product will be equal to 14 because 76 is a fraction and fractions keep the number the same.
- The product will be greater than 14 because you add 14 six-sevenths more times.
Explanation: The size of a factor in multiplication directly influences the size of the product compared to the other factor. When you multiply by a number greater than 1, the product becomes larger than the original number. When you multiply by a fraction less than 1, the product becomes smaller than the original number. In the expression (76 × 14), since (76) is less than 1, the product will be less than 14. A common misconception is confusing multiplication with addition, like thinking you add the number multiple times instead. By focusing on the factor's relation to 1, you can predict the product's size without calculating it fully. This helps in practical situations, like buying partial packs, and strengthens conceptual understanding over rote computation. Question 15
A student is thinking about 141×16. The factors are 141 and 16. Without calculating, which statement best describes the size of the product compared to 16?
- The product will be greater than 16 because 141 is greater than 1, and multiplying by a number greater than 1 makes the product larger. (correct answer)
- The product will be less than 16 because 141 is a fraction, and fractions always make products smaller.
- The product will be equal to 16 because multiplying by 141 does not change the number.
- The product will be greater than 16 because you add 16 and 141.
Explanation: The size of a factor in multiplication directly influences the size of the product compared to the other factor. When you multiply by a number greater than 1, the product becomes larger than the original number. When you multiply by a fraction less than 1, the product becomes smaller than the original number. In the expression (141 × 16), since (141) is greater than 1, the product will be greater than 16. A common misconception is that mixed numbers, being part-fraction, always decrease the product, but those greater than 1 actually increase it. By comparing the mixed number to 1, you can determine the product's relative size without full computation. This technique fosters deeper understanding and efficiency in estimating outcomes. Question 16
A student works with 7×71. The factors are 7 and 71. Since 71 is less than 1, multiplying by it makes the product smaller than 7. Which statement is correct about the product compared to 7 (without calculating)?
- The product is greater than 7 because multiplication always makes numbers larger.
- The product is less than 7 because 71 is less than 1. (correct answer)
- The product is equal to 7 because the numerator is 1.
- The product is greater than 7 because 7+71 is greater than 7.
Explanation: The size of a factor in multiplication directly affects the size of the product compared to the other factor. When you multiply a number by a factor greater than 1, the product becomes larger than that original number. Conversely, multiplying by a fraction less than 1 results in a product that is smaller than the original number. In the expression 7 × 1/7, since 1/7 is less than 1, the product will be less than 7. A common misconception is that multiplying by a fraction related to the number keeps it the same, but only multiplying by 1 does that. By reasoning about factor sizes, you can compare the product without full multiplication. This technique streamlines thinking and avoids detailed arithmetic.
Question 17
A student is working with the multiplication expression 8×45. The factors are 8 and 45. Since 45 is greater than 1, multiplying by it makes the product larger than the other factor 8. Which statement explains the size of the product compared to 8 (without calculating)?
- The product is less than 8 because any fraction makes a product smaller.
- The product is equal to 8 because multiplying keeps the number the same.
- The product is greater than 8 because 45 is greater than 1. (correct answer)
- The product is greater than 8 because you add 45 to 8.
Explanation: The size of a factor in multiplication directly affects the size of the product compared to the other factor. When you multiply a number by a factor greater than 1, the product becomes larger than that original number. Conversely, multiplying by a fraction less than 1 results in a product that is smaller than the original number. In the expression 8 × 5/4, since 5/4 is greater than 1, the product will be greater than 8. A common misconception is that fractions always make products smaller, but this depends on whether the fraction is less than or greater than 1. By reasoning about factor sizes, you can compare the product to one of the factors without performing the full calculation. This approach saves time and helps build an intuitive understanding of how multiplication works with fractions.
Question 18
A recipe uses the multiplication expression 3×32. The factors are 3 and 32. Since 32 is less than 1, multiplying by it makes the product smaller than the other factor 3. Which statement is correct about the product compared to 3 (without calculating the exact product)?
- The product is greater than 3 because multiplication always makes numbers larger.
- The product is less than 3 because 32 is less than 1. (correct answer)
- The product is equal to 3 because one factor is a fraction.
- The product is greater than 3 because you add 32 to 3.
Explanation: The size of a factor in multiplication directly affects the size of the product compared to the other factor. When you multiply a number by a factor greater than 1, the product becomes larger than that original number. Conversely, multiplying by a fraction less than 1 results in a product that is smaller than the original number. In the expression 3 × 2/3, since 2/3 is less than 1, the product will be less than 3. A common misconception is that multiplication always makes numbers bigger, but this is not true when multiplying by fractions less than 1. By reasoning about factor sizes, you can compare the product to one of the factors without performing the full calculation. This approach saves time and helps build an intuitive understanding of how multiplication works with fractions.
Question 19
A student is using the expression 52×15. The factors are 52 and 15. Since 52 is less than 1, multiplying by it makes the product smaller than the other factor 15. Which statement is correct about the product compared to 15 (without calculating)?
- The product is less than 15 because 52 is less than 1. (correct answer)
- The product is greater than 15 because multiplication always makes numbers larger.
- The product is greater than 15 because 52 is a fraction.
- The product is equal to 15 because you are combining two numbers.
Explanation: The size of a factor in multiplication directly affects the size of the product compared to the other factor. When you multiply a number by a factor greater than 1, the product becomes larger than that original number. Conversely, multiplying by a fraction less than 1 results in a product that is smaller than the original number. In the expression 2/5 × 15, since 2/5 is less than 1, the product will be less than 15. A common misconception is that multiplication always enlarges numbers, but factors less than 1 actually shrink them. By reasoning about factor sizes, you can compare the product without calculating the exact value. This approach saves effort and builds intuitive math skills.
Question 20
A coach writes the multiplication expression 23×10. The factors are 23 and 10. Since 23 is greater than 1, multiplying by it makes the product larger than the other factor 10. Which statement is correct about the product compared to 10 (without calculating)?
- The product is less than 10 because fractions always make products smaller.
- The product is greater than 10 because 23 is greater than 1. (correct answer)
- The product is equal to 10 because 10 is a whole number.
- The product is greater than 10 because 23+10 is bigger than 10.
Explanation: The size of a factor in multiplication directly affects the size of the product compared to the other factor. When you multiply a number by a factor greater than 1, the product becomes larger than that original number. Conversely, multiplying by a fraction less than 1 results in a product that is smaller than the original number. In the expression 3/2 × 10, since 3/2 is greater than 1, the product will be greater than 10. A common misconception is that all fractions reduce the product size, but fractions greater than 1 actually increase it. By reasoning about factor sizes, you can compare the product to one of the factors without performing the full calculation. This approach saves time and helps build an intuitive understanding of how multiplication works with fractions.