I am a college student and I am to answer the following question: Describe ways of telling by simple inspection when a fraction has a value close to 0; close to 1/2; and close to 1. I am to imagine that I am a 3rd grader answering this question. Any thoughts please?

Whatever you do don't let them see a calculator. There is a real sense of how ratios of numbers are related to each other, and the inspection of numbers, such as numerators and denominators of a fraction, is more likely to help developing it than senseless crunching on calculators.

Relate the fraction to something that they know about. For example suppose that you are going to buy a package of marbles and you want to know how much they cost per marble. The fraction is cents/marbles. Suppose that you have the choice of paying 89 cents for 95 marbles, or 23 cents for 49 marbles, or 1 cent for 7 marbles. That gives a bit of the meaning of fractions with value close to 1, to 1/2 and to 0.

Cheers,
Penny