N3D4TNp25

Answers to Problem 25:

1.   76 and 43

2.   18 and 43

3.   18 and 25

TEACHER NOTES:

Estimation serves as an important companion to computation. It provides the tool for judging the reasonableness of calculator, mental, and paper-and-pencil computations. Being able to compute exact answers does not automatically lead to an ability to estimate or judge the reasonableness of an answer. Students in grades 3–5 will need to be encouraged to routinely reflect on the size of anticipated solutions.[1]