## Chapter 10: Mental Math and Estimation

In this chapter, your child will learn strategies to do mental addition and subtraction when an exact answer is needed. Your child will also learn how to estimate when an exact answer is not needed.

Some of the skills your child will practice are:

Some of the skills your child will practice are:

- using place-value and number-bond strategies such as
*adding 10 and subtracting extra ones*and*adding 100 and subtracting extra tens*to help with mental addition and subtraction - using number lines to round numbers to the nearest ten
- estimating sums and differences to check reasonableness of answers

Vocabularysum add mentally |
difference subtract mentally |
number line about |
round nearest ten |
estimate reasonable |