This time we are answering

5 × ? = 35

We could do this in our heads easily (right?), but if the problem is more complicated, we need to know what to do.

On the left, we are multiplying by 5. The opposite of multiplying by 5 is dividing by 5. So we divide both sides by 5 and we get:

CHECK: 5 × 7 = 35. It checks out okay.

[These checks seem silly with easy examples, but it is a really good idea to check your solutions for all the equation problems that you do. It means you can leave the problem feeling good that you have the right answer and also, you learn more about how the solution works.]