I saw this idea at a Math Workshop and loved it. It's a simple way to help children use the number grid effectively when adding and subtracting. The numbers in the 10's column are colorcoded to match the number in the 1's column that would come next. I used markers to outline each number grid that my students have on their desks. This is a computer version to download.
Here is a second version for people using a Math series that has a number grid in a different direction.
Here is a third version. This one is a much smaller version so you can print them out and tape them onto student's desks.