## CHAPTER 3: ADDITION AND SUBTRACTION STRATEGIES

**Lesson 1: Using Addition Strategies**

**Goal**

Add 1-digit numbers using mental math strategies.

**Instructions for Use**

In Space Shuttle Launch, you can use mental math strategies to solve 1-digit addition problems.

Click on the astronaut to start. Choose Addition and Easy in the following screens. Click the numbers on the pad at the left to solve the math problem shown on the screen. A correct answer leads to the success of the mission; an incorrect answer causes the mission to fail.

In Guitar Hero, you can use mental math strategies to solve 1-digit addition problems.

Leave the skill as “Addition,” leave the first operand as 1, change the second operand to 9, and leave the level at “Beginner.” Then you may enter your name at the bottom and click “Start.” Press any key to start the game, then read the addition problem as it comes down the screen. Use the arrow keys or “ASDFG” keys to move from side to side to select the correct answer. Leave your answer highlighted until the addition problem reaches the bottom of the screen. If your answer is correct, a point will appear in the green circle. If your answer is incorrect, or if you do not choose an answer before the problem reaches the bottom, a point will appear in the red circle.