# Surf for More Math

## Chapter 8: Addition and Subtraction Strategies

**Lesson 1: **Counting On and Back on a Number Line

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

**Goal**

Count on and back to determine sums and differences.

[C, Me, PS, R, V]

**Instructions for Use**

**Addition Number Line** allows student to use this virtual number line to help them solve addition sentences.

Use the number line to help you solve the addition sentence shown. Type your answer in the empty text box. Click “Check” to check your answer. Click the arrow to try another addition sentence.

**Subtraction Number Line** allows student to use this virtual number line to help them solve subtraction sentences.

Use the number line to help you solve the subtraction sentence shown. Type your answer in the empty text box. Click “Check” to check your answer. Click the arrow to try another subtraction sentence.

**Using a Number Line** allows students to see addition and subtraction sentences represented on a number line.

Look at the number line and the number sentence. Click “Go” to see the number sentence modelled on the number line. Click "New Problem" to see another number sentence appear. Click the subtraction symbol (-) to see some subtraction sentences modeled on the number line.