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 ...

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 ...

To add -4 and 5, draw the starting number on a number line and count to the right when adding numbers. What is the difference in temperature between a desert at 40 °C and a mountain top at -2 °C? \(40 ...