Bill and Bernie use labelled balloons to show subtractions of 10 from several two-digit numbers which are less than 100. Bernie thinks of a number and Bill must subtract ten from that number.

First broadcast:
5 November 2001

Use this clip as a starter to a subtraction lesson. After watching the clip display on the board '- 10 = ?' Give the pupils mini whiteboards to record their answers. Stand at the front of the subtraction and quick-fire display a two-digit number. Give the pupils a five second countdown to write their answers before they show you. Repeat several times with a range of two-digit numbers.