They're also available for nearly all grade levels. There are printable middle school, high school, elementary school, and even pre-school worksheets.
However, caution must be taken into account when review is repeatedly covered in your classroom. You do not want your students to become bored or frustrated with the repetition.
For example, since I want to make sure my students get accustomed to reviewing the various math concepts and standards we've learned all year, I have them practice regularly. I want them to get to a point where they are so familiar with grade level math content, that solving these types of problems becomes automatic.
Ratios and proportions are likewise wonderful math lessons with plenty of interesting practical applications. If three pans of pizza, one kilo of spaghetti, two buckets of chicken can properly feed 20 hungry friends, then how much pizza, spaghetti and chicken does mom need to prepare for birthday party with 30 kids?