We're going to look at how addition and subtraction are related, and number lines can help us with that. Do you recall how to use a ?
Use the number line to help you find the value of 35-24.
We can see how addition and subtraction are related by looking at their fact families, just like in this video.
Use the fact family of 5, 7 and 12.
What is 5+7?
What is 12-7?
What is 12-5?
uses mental and written strategies for addition and subtraction involving two-, three-, four and five-digit numbers