# Surf for More Math

## Lesson 2 **- Estimating Sums and Differences**

To encourage your child to have fun on the Web
while learning about Estimating Sums and Differences, here are some
games and interactive activities they can do on their own or in pairs.

**Goal**

Estimate sums and differences to solve problems.

**Builds Upon **

Student Book pages 110-111

### Instructions for Use

** **

Estimation
Contraption helps your child estimate sums.

To use Estimation Contraption, estimate the sum of the column of numbers,
and 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 using rounding.

** **

To use Estimating Sums by Rounding
, click the 'Start Addition' button. Estimate the sum between the two
numbers and press the numeric button closest to your estimation.

** **

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

** **

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