Create a pretend grocery store. Stock the "store" with items clearly marked with prices that cost only a few cents. Give each of the children a dollar's worth of change, and let them go shopping. Rotate the children through the role of cashier, which gives them a sense of how to both add and subtract numbers while making change.
Ask children to subtract the number of days until their birthdays or an upcoming holiday. This exercise not only teaches them a sense of time, but reinforces subtraction rules -- particularly as the celebrated day draws near.
Collect groups of blocks to illustrate the relationship of numbers in subtraction. Assemble 100 multicolored blocks, and ask the children to subtract any given number -- piling them in a second stack. Seeing the relationship between the two stacks helps illustrate the size of the numbers as blocks are subtracted.
Team up students with subtraction flash cards -- a great way to go through a large number of problems very quickly. Teaming up students makes the process more fun, allowing children with weaker math skills to learn from kids with a stronger grasp of the subject.
Purchase some small candies, and use them to illustrate subtraction. For instance, if you have 10 candies and eat two, how many are left? Using a familiar food or snack helps hold the kids' interest and increases the amount of fun as they determine the correct answers. As a bonus, give children a piece when they give a certain number of correct answers.
Illustrate subtraction problems in everyday situations. Use a trip to the park or library as a way to have a teaching moment. Ask the children subtraction questions tied into what they are seeing and experiencing. This helps connect the child to the importance of subtraction in everyday life.