This tool has been so helpful for my students' understanding of multi-digit addition and subtraction! The columns help them keep their ones, tens, hundreds, and thousands straight. I've included several different versions for you to choose from. Instructions for use: I like to print these and stick them in a sheet protector. That way, my students can use dry erase markers and use these again and again. They can be used for whole group, small group, or individual practice.