This video explains how to subtract by rounding to tidy numbers and then compensating. One of the mental strategies we can use to quickly subtract. I would like to thank Antonio who taught me how to download a ShowMe presentation onto my iPad using an app Free Video, and then placing the presentation into iMovie. I hope many of you will be making similar Maths movies. We will keep them on our wiki page here.
Would videos like these be helpful in Maths?