Can you find a three-digit number that totals 25 when individual digits are added together? There is more than one correct answer.

First broadcast:
14 September 2007

A useful starter or plenary. Extend the idea from the clip to give the pupils an opportunity to carry this out independently or in small groups. Tell the class that you would like them to create a three-digit number and all three digits must add up to 21. Give them some time to carry this out then ask pupils to come to the front to explain their strategies to the rest of the class.