Review subtraction of 2 numbers whose sums would be 18 or less
How much money do I have left if I buy a soda? By the end of the week, how much of my daily allowance will I be able to save if I don't?
However for the most part, when a worksheet is needed to help drill down a procedure, standard, or lesson, its effectiveness can and will vary.
Therefore it is our job as the teacher to make sure that when we need to utilize a worksheet, we provide the students with one that is as inspiring as can be.