Two groups of students were tested to compare their speed working math problems. Each group was given the same problems. One group with calculators, the other group without calculators. What is the independent variable, the dependent variable and constant variable?

The independent variable is the variable being changed. In this case, the independent variable is the calculators. The dependent variable is essentially what you are looking for that depends on the independent variable. In this case it would be time. The constant variable or controlled variable are something that doesn't change and would skew the results. One may be the exact same problem for both groups. Try to come up with two more.