How many kids in school have done their homework? Again this can be answered in several ways: in percentages, 70%; or in ratio, 7:10; Both of these mean out of ten kids in class there are seven good ones who did and three not-so-good ones who didn't. The bottom line is that kids learn math much better when it makes sense.
Worksheets also, when used properly, provide both the students and parent / tutor immediate feedback as to the child's progress. This means they can be used to point out areas where the student needs further reinforcement.
From a teacher's perspective our competition is tough. Passing out a handout of 30 problems that are all in a format of 534x25= is not as stimulating in the students' eyes as playing games such as Grand Theft Auto and Resident Evil.
My students are engaged in the activity because they are always eager to find out what the next scene will be, and how the math problems will be nestled within. They also like how within each handout I inscribe the title in a way that fits with the theme of that particular scene - another attention catching technique. And since this review activity only takes about fifteen minutes of class time, it is quick yet extremely beneficial.