The song describes the different words used to mean subtract. It states that when you take something away, you end up with less than you had before.
Listen to the song. Use this as a stimulus for the children to understand what subtraction means. Get the children to write down as many words for subtraction as they can. They can also use this as a memory exercise, where they write on their whiteboards as many different subtraction facts as they can that feature in the clip. From this they can then use a variety of everyday objects and apparatus to create a variety of subtraction calculations (with their inverse) by practically working these out, eg 20 - 5 = 15, 15 + 5 = 20. This will help reinforce their number bonds too. To stretch the more able, you can use this song to help find the missing number in the number sentence eg 5 + ___ = 21?