Assessing the Reasonableness of Sums Using Regrouping

The video tutorial explains how to assess the reasonableness of sums using regrouping. It introduces the concept of checking answers for mathematical sense and provides examples with Anthony and Colin's addition problems. The tutorial demonstrates how to use regrouping and estimation to verify if the sums are reasonable, highlighting the importance of checking both the tens and hundreds places. The video concludes by emphasizing the effectiveness of the regrouping strategy in estimating sums accurately.

What is one method to verify the correctness of an answer in addition problems?

• Using a calculator

• Asking a friend

• Checking the reasonableness

• Rewriting the problem

In the example with Anthony, what was the estimated sum using regrouping?

• 199

• 200

• 150

• 250

Why was Anthony's answer considered reasonable?

• It was close to the estimate

• It was exactly the same as the estimate

• It was a round number

• It was a multiple of ten

In Colin's example, what was the estimated sum using regrouping?

• 1400

• 1600

• 1500

• 1782

Why was Colin's answer not considered reasonable?

• It was a negative number

• It was a decimal

• It was too far from the estimate

• It was a prime number