# Surf for More Math

## CHAPTER 3: ADDITION AND SUBTRACTION STRATEGIES

**Lesson 3: Adding and Subtracting Tens**

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

**Goal**

Relate adding tens to addition and subtraction facts.

**Builds Upon**

Student Book pages 62–63

**Instructions for Use**

Adding Tens allows students to practise adding tens.

Scroll down to the section that reads “Practice,” then click “Start.” Read the addition question, then type your answer in the box beside the = sign. Click “Check” to check your answer. For an extra challenge, you may scroll down to the “Play” section below and click on “Countdown,” “Give Me Time,” or “20 Questions” to be timed as you answer the questions.

Subtracting Tens gives students practise at subtracting tens.

Scroll down to the section that reads “Practice,” then click “Start.” Read the subtraction problem, then type your answer in the box to the right of the = sign. Click “Check” to check your answer. You may also click on “Countdown,” “Give Me Time,” or “20 Questions” in the “Play” section to be timed as you answer the questions.

Number Sentences to 100 (SMART Notebook-Compatible) allows students to practise adding tens to make 100. Pages 5 to 11 are the most appropriate for this lesson. You should set this activity up for students. You may want to adapt the SMART Notebook file to suit your class.

Follow the directions to answer the questions, as directed on each page.