Explain how you could use a number line to find the number that is 9 less than 1.

Count nine spaces left of 1.

To use a number line to find the number that is 9 less than 1, you would start by locating the number 1 on the number line. Imagine a horizontal line with zero at the center and positive numbers increasing to the right and negative numbers decreasing to the left.

1. Begin by finding the number 1 on the number line. It would be somewhere to the right of the center, representing positive numbers.

2. To find the number that is 9 less than 1, you need to move to the left by 9 units. Each unit on the number line represents one whole number.

3. Count 9 units to the left from the number 1.

4. The number you reach after moving 9 units to the left from 1 on the number line is the number that is 9 less than 1.

In this case, if you start at 1 and move 9 units to the left, you will end up at -8. So, the number that is 9 less than 1 is -8.