Hello!
The independent variable here is whether or not the group received a calculator. This is the factor that is being changed, and this is what is going to affect the results of the test.
The dependent variable in this case is the seventh graders' speed solving the integer problems. This is because this is the variable being affected by the independent variable - whether they have a calculator.
The controlled variables in this case would be both groups are seventh graders, and they are both solving integer problems. These need to maintain constant as if not, they can affect the dependent variable as well.
Hope this helps!
