Use number line and add the following integers: 9 + ( - 6).

To solve the problem \( 9 + (-6) \) using a number line:

1. **Understand the problem**: We are adding a positive integer (9) and a negative integer (-6). This involves moving to the right for positive numbers and to the left for negative numbers on the number line.

2. **Draw a number line**: Draw a horizontal line and mark numbers from -10 to 10, ensuring that zero is at the center.

3. **Start at 0**: Place your finger or pointer at 0.

4. **Move to 9**: Since the first number is 9, move 9 units to the right of 0. You will now be at 9 on the number line.

5. **Add -6**: Adding -6 means moving 6 units to the left from 9. Starting at 9, move back by 6 steps. You will land on 3.

6. **Result**: The result of \( 9 + (-6) \) is 3.

**Final Answer**: The sum of \( 9 + (-6) \) is 3.