Question

Mr. Walters asked his students to order 89, 708, 37, and 93 from least to greatest, and to be ready to explain the process they used to order the numbers.One student, Brianna, ordered the numbers correctly, and when Mr. Walters asked her to explain her process, she said, “The numbers 89, 37, and 93 are less than 100, so they are all less than 708, since that is greater than 100. Also, 37 is the least because it comes before 50 and the other two numbers are close to 100. Then 89 is less than 90, but 93 is greater than 90.”Which of the following best describes the strategy on which Brianna’s explanation is based?

Answer 1

Option B is correct.


Brianna first indicates that 708 is the greatest number because it is greater than 100, while 37, 89, and 93 are all less than 100.

Next, Brianna indicates that 37 is the least number because it is less than 50, while 89 and 93 are greater than 50. Finally, Brianna recognizes that 89 is less than 93 because 89 is less than 90, while 93 is greater than 90.

Thus, over the course of her explanation, Brianna used 100, then 50, and then 90 as points of reference for comparisons, which is exactly what benchmark numbers are points of reference for comparison.

Brianna did not count between any of the numbers, estimate the numbers, or use the place values in any of the numbers to make her comparisons, so the other options do not describe the strategy on which Brianna's explanation is based. :)