# Surf for More Math

## CHAPTER 3: ADDITION AND SUBTRACTION STRATEGIES

**Lesson 7: Investigating Fact Families**

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

**Goal**

Model and record fact families.

Demonstrate the effect of adding 0 to or subtracting 0 from any number.

[C, ME, PS, R]

**Instructions for Use**

**Inverse Relationship for Addition and Subtraction** lets students investigate the inverse relationship between addition and subtraction.

To use Inverse Relationship for Addition and Subtraction, click the "Start Add/Subtract Relationship" button. Decide what number should replace the question mark. Click the numerical button.

**Fact Families** provides students with practice on working with fact families for addition and subtraction.

To use Fact Families, enter the missing fact equation in the space provided. Click “Submit” to check your answer. When you have completed a certain number of questions, click “Submit & finish” to view a summary of your score.