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.
They're also available for nearly all grade levels. There are printable middle school, high school, elementary school, and even pre-school worksheets.
As a middle-school math teacher, I have seen many students who do understand abstract concepts, and even enjoy learning about things like Pi and the Pythagorean Theorem, but who appear to be unable to do so due to a weak grasp of math fundamentals.
Why use free math worksheets? Easy. These worksheets can save you a lot of time and money and when you're a busy homeschool mom teaching several children, this means a lot.