Mathematics 5

# Surf for More Math

## Lesson 2 - Estimating Sums and Differences

Use these interactive games and activities to encourage your child to have fun on the Web while learning about estimating sums and differences.

### Goal

Estimate sums and differences and justify your strategy.

### Builds Upon

Student Book pages 98-99

### Instructions for Use

Estimation Contraption allows your child to estimate sums using strategies such as rounding.

To use Estimation Contraption, estimate the sum of the column of numbers and then input the answer in the field below the column. Click "OK" to check if the answer is correct. Try the next question.

Estimating Sums by Rounding allows your child to estimate the sum of two numbers by rounding.

To use Estimating Sums by Rounding, scroll down and click the "Start Addition" button. Estimate the sum of the two numbers by rounding and press the numeric button closest to your estimation.

Estimating Differences by Rounding allows your child to estimate the difference of two numbers by rounding.

To use Estimating Differences by Rounding, scroll down and click the "Start Subtraction" button. Estimate the difference between the two numbers by rounding and press the numeric button closest to your estimation.