CHAPTER 6: Addition and Subtraction of Integers

To use the Integer Explorer to add integers, follow these steps:

1. Click "Set Target".
2. Click "Random Sum Target" and then click "OK".
3. The grey box in the top left corner displays the addition question that you are trying to solve.
4. Click "First Addend (1)".
5. Click the "+" or "-" button depending on whether the first number in the question is a positive or negative number.
6. Click the squares on the grid to represent the first number in the question.
7. Click "Second Addend (2)".
8. Click the "+" or "-" button depending on whether the second number in the question is a positive or negative number.
9. Click the squares on the grid to represent the second number in the question.
10. Click "Sum (R)".
11. Click "Select".
12. Drag the pointer over all the blocks on the grid, and then click "Simplify". The explorer will automatically pair up all the negative and positive integers and delete them.

• The number of positive or negative squares left on the grid represents the answer to the question.

To practice pairing up negative and positive integers, perform steps 1 to 9 and then arrange the negative and positive squares on your grid so they are in pairs. (To move a square, use your mouse to drag the square to a different location.) Click "Select". Then select each pair and drag each pair to the area with the recycle symbol. The number of positive or negative squares left on the grid represents the answer to the question. Click "Sum (R)" to check your answer.

To use Integer Explorer to subtract integers, follow these steps:

1. Click the "Set Target".
2. Click "Random Difference Target" and then click "OK".
3. The grey box in the top left corner displays the subtraction question that you are trying to solve.
4. Click "Show / Help" and then click the "5" button in the bottom right corner of your screen.

• A yellow box will appear to help you through the subtraction steps for the question.
• Repeat steps 1 and 2 and try another question on your own, in other words without using the Show / Help feature.

You can also enter your own addition or subtraction questions into the Integer Explorer. Just click "Set Sum Target" or "Set Difference Target" in step 2.