This is a hard concept for many students. Therefore, I have differentiated this center so that it can meet the needs of all your students by having multiple ability levels. This is 3 centers in one, with answer sheets and an instructional card for each center. I have also included a page after each center card that displays the same card smaller so that they can fit on the small clear cases that many people use to store their centers in.
***There are both colored and black and white versions of all these centers and materials.***