This is a PDF with 24 problems and answers that can be used for a matching game, or for grouping. To pair students, pass the cards out, then let them walk around the room to find their solution for the question mark. When printing this activity, choose the option to print 4 images per page. If you want the cards smaller, then you can print 6, 9, or 16 images per page. You could print them on your choice of colored paper, laminate them, then cut them out. Make sure to mix them up each time you use them. These will print well in black and white also.
*If you would like different colors, please contact me!