Finding the difference, or subtracting, is one of the most basic concepts in math. This skill is required to learn more complex operations like multiplication and division. It is also required to understand decimals and fractions. Without learning how to subtract, students cannot move forward in their understanding of numbers.

#### Percentage Difference

When comparing two values, you may be asked to calculate the percentage difference. This is calculated by dividing the difference of the two values by their average and multiplying by 100. Percentage differences are often used to measure the amount of change in a number over time or between two similar numbers.

#### Using the ‘Constant Difference’ Strategy

One way to help students develop an understanding of the concept of difference is to teach them about a constant difference. This strategy allows students to compensate for their subtraction equations by adding or subtracting from both sides of the equation in order to maintain a consistent difference between the two numbers. It is important to start students with this strategy at a lower grade level and use a variety of tools to support their understanding, including the number line.

When learning to find the difference between fractions, it is helpful to have a visual reminder of the process. One method is to compare the two fractions by finding their lowest common denominator, which can be done by converting each of the fractions into an equivalent fraction with the same denominator. Once this step is complete, you can then subtract the numerator of the first fraction from the numerator of the second fraction to obtain the difference.