These are problems that can manipulated so that students understand what it means to substitute when solving system of equations. I created this for my class because I found that they were having trouble seeing that you replace the x or y in one equation with its’ equivalent and that when you do that, the variable it replaces is gone. I printed these on bright cardstock, laminated them, and then put some magnetic tape on the back so that they can be manipulated on the white board. I suggest you cut close to the numbers and symbols that way you can place them close to each other when you place them on the board. These could also be used at a center or in groups.