A numerical input problem accepts a line of text input from the student, and evaluates the input for correctness based on its numerical value.

The answer is correct if it is within a specified numerical tolerance of the expected answer.

Enter the approximate value of 502*9:

Explanation

Although you can get an exact value by typing 502*9 into a calculator, the result will be close to 500*10, or 5,000. The grader accepts any response within 15% of the true value, 4518, so that you can use any estimation technique that you like.