Hello, I'm Mr Firth, and I need your help today as we learn to add and subtract within ten. You can use lots of things to help you add and subtract. Counters, number lines and even your fingers. Let's ...

A number line can be useful when answering questions involving negative numbers. When adding a positive number, go up the number line (move to the right). When subtracting a positive number, go down ...

Addition & subtraction strategies to solve two-digit equations using an open number line. In this lesson, students go over using different addition and subtraction strategies to solve two-digit ...