- 1). Write down a math problem that is easy to solve. For example, you could use 2*2+1=5.
- 2). Choose a number from the problem to substitute. Substitution is when you take a number and replace it with something else. Insert a "y" for the number, such as 2*y+1=5.
- 3). Solve the equation to make sure each sign is equal. Follow the order of operations. First Multiply 2 and y to get 2y. Now subtract 1 to the other side of the equation, to isolate y. The problem now appears as 2y=4. Each y is equal to 2, which was the original number before it was substituted, meaning the equation is true.