Choose a model to use in the teaching process. Items that students see everyday, such as apples, oranges or erasers, are the most effective.
Ensure that you have enough models to complete the problem. To do this, find the larger of the two integers in the subtraction problem. You must have more models than this integer. For example, if the problem is 8 - 4, you must have at least 8 apples.
Present the problem to the students. Lay out the models in a line to represent the first integer value. For example, if the problem is 8 - 4, lay out eight apples. Count out the apples one through eight with the students.
Remove the number of apples that are being subtracted. In our example, remove four apples. Count out the four apples with the students and remove them from the line one at a time.
Count the remaining apples with the students to yield the result of the subtraction problem. In our case, count out the remaining four apples.