## CHAPTER 3: ADDITION AND SUBTRACTION STRATEGIES

**Lesson 3: Adding and Subtracting Tens**

**Goal**

Relate adding tens to addition and subtraction facts.

**Instructions for Use**

Adding Tens allows you 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 you 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.