A catchy animated song is used to show how simple it is to add single-digit numbers to 100.
Children could use money to find totals. They could have a pound coin which they could learn is 100p. They could then take other coins from a bag, each time working out the total. As they improve, more pound coins could be added, or children could add three other coins to the pounds. They could show answers as pence, then convert them into pounds.