The “colored counter” method is an old tried-and-true method for teaching the concept of adding signed numbers. However, to show subtraction with the colored counter method has always seemed painful to me … that is, until I altered the method slightly.
Now all problems are demonstrated within a “Sea of Zeros” and when you need to take away counters, you can simply borrow from the infinite sea. Voila! Here’s a short video to demonstrate addition and subtraction of integers using the “Sea of Zeros” method. You can print some Colored Counter Paper here.