Review the subtraction of positive numbers. By reviewing the subtracting of positive integers, the students will be reassured that they understand the process fully. For example, you can do the problem 7 - 6 = 1.
Introduce a subtraction problem with positive integers, but with an answer that will result in a negative integer. Use a number line to help demonstrate the process. For example, 5 - 7 = -2.
Explain how different signs combine to form different expressions. One of the elements which may confuse students learning how to subtract integers is the placement of positive and negative signs next to one another. A positive sign and a positive sign results in a positive sign. A positive sign and a negative sign results in a negative sign. For example,
4 + (-2) = 4 - 2. A negative sign and a negative sign results in a positive sign. For example, 4 - (-2) = 4 + 2.
Do practice sheets with the same types of subtraction problems repeated at least 10 times. For example, do 10 practice problems that involves subtracting a positive number from a negative number. Then, do 10 practice problems that involve subtracting a negative number from a negative number. You can time yourself and see how rapidly you can complete the worksheets.
Create flash cards that involve different types of subtraction problems. Put the problem on the front and the answer on the back. Using flash cards is a beneficial way to practice the subtraction of integers because they help you to build up your speed and not have to work out every problem on scrap paper.