Math Help: Creating a Number Line

How to Make a Number Line

Number lines usually include both positive and negative numbers. You can just make a short number line to help you solve a problem with lower numbers, or you can make a long number line that wraps all the way around the walls of your classroom. Either way, the process is the same:

1. Gather a piece of paper and a pencil, and then mark a dot in the center of the paper. This point will be the zero on your number line. Next, draw a horizontal line through the zero point.
2. Working from zero and moving to the right, divide the line into equal sections and label them with the positive numbers (1, 2, 3…).
3. Do the same thing on the left side of zero, this time labeling the marks with the negative numbers.

Variations

If you'd like to make your number line a bit more interesting, there are lots of creative options. Here are a few ideas:

1. Make your number line vertical instead of horizontal, like a thermometer. The positive numbers go on the top half of the line (above zero), and the negative ones go on the bottom (below zero).
2. Use colored pens or markers to decorate your number line. For example, positive numbers could be red, and negative numbers could be blue.
3. Tailor your number line to the problem you're working on. For instance, if your math problem is about the distance a train is traveling, you could label your number line in miles and create a legend to show the directions.

Using Your Number Line

Now that you've made yourself a number line, you might need some instructions on how to use it. First, keep in mind that number lines are most helpful for adding and subtracting positive and negative numbers. Here's how to use your number line to solve this kind of problem:

1. The first number in the problem is your starting point on the number line. For instance, if your problem is -5 + 7, then your starting point is negative five.
2. The sign in the middle of your problem tells you which direction you need to go from the starting point. In the problem -5 + 7, the '+' sign tells you to go to the right. If it were a '-' sign, you'd move to the left.
3. The second number in the problem tells you how many spaces on the number line you should go in the chosen direction. In our example problem, you go seven spaces to the right.
4. The number that you land on is your solution. Since positive two (2) is seven spaces to the right of negative five (-5), the answer is two (-5 + 7 = 2).