N3D3TNp24

Answer to Problem 24: Answers may vary. Example: 130 – 40 = 90

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 the 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]