Generally, using the dice with the egg crate only fractions, the learner enhances the instruction received from working with an actual egg crate. The dice add a randomness to the problem choices that allows the learner to focus on the skill, not just memorizing the numbers.  That makes the dice/key combination superior to a simple worksheet.  The dice always keep the learner in the game, because they never know what precise problem will come up when they roll the dice.  That way, they can practice to mastery, not just the completion of a worksheet.  Finally, by mixing in the non-egg crate fraction dice, you can generate even more difficult math problems.

The teacher can set goals for the students, such as “get 10 out of 10 right” or “get 20 out of 20 right,” making the exercise dynamic rather than static.

The teacher can also use the Fraction Key for easy test writing.  Since you now have access to an exhaustive database of problems, you can easily choose questions that target the skill you wish to exercise.  For example, you might want to choose a division problem that has no cancelling, so pick ½ divided by 1/3.  Or you might want a division problem that has cancelling and changing the improper fraction result to its mixed number, such as 5/6 divided by 7/12.  Since they are all laid out for you, their selection for your test will be a simple process.