 Overview Printables Interactive Video

# Number Line

## What is a number line?

A number line is a useful tool, ideal for mathematics instruction in elementary classrooms and other places of learning. A number line is exactly as it sounds – it’s a straight, horizontal line with numbers placed at equal distances along its length. The numbers on a number line get larger as you move from left to right and get smaller as you move in the opposite direction.

## Why is it important to use number lines?

Ordering numbers is an essential skill in mathematics. Number lines are a perfect model for showing relationships between numbers. Research shows that number lines promote the development of mental math proficiency. Students can clearly visualize the sequencing of numbers and easily demonstrate strategies used to calculate the answer.

Number lines are helpful at all levels of elementary mathematics and can be used to practice a multitude of math concepts. This includes learning how to count, add, subtract, multiply, divide, and understand fractions. When using a number line to add, you simply move forward. It is easier to start with the larger number and jump forward according to the smaller number. If solving 5+3, you would start at 5 and hop forward 3 times to reach a sum of 8.  When using a number line to subtract, you move backward. To multiply, you skip count from left to right on the number line. Here is an example of how to multiply using a number line. If a student is asked to find the product of 5 X 3, they can move along a number line by threes 5 times to reach the product of 15.