# Surf for More Math

## Chapter 6: Addition and Subtraction

**Lesson 4: Exploring and Representing Equality **

Use these interactive activities to encourage students to have fun on the Web while learning about addition and subtraction. Students can try these activities on their own or in pairs.

**Goal**

Use a pan balance to explore equal and not equal, and record equalities using the = sign.

[C, CN, PS, R, V]

**Instructions for Use**

**Pan Balances** allows students to create equivalent number sentences.

This site has a pan balance. Click on one side of the balance. Type a number sentence. The balance will react, depending on which side has a larger number. Then type a different number sentence that has the same answer on the other side of the balance. You will see how the scale will balance. Be sure to create both addition and subtraction sentences.