Subtraction Written Methods

Throughout their years at school, children should progress from informal jottings, practical taking away and number line methods to formal efficient written methods. By the end of Year 3, children should be confident using short efficient written methods for all four operations + - x ÷ Children become secure with these methods with regular practice and should be able to apply skills to problem solving.

Blank Number Line An empty number line helps children to count back and forward to subtract amounts. Children begin jumping back and progress onto complimentary addition to count forward to find differences. Counting back Complimentary Addition 45 – = 23

Your Turn! Can you use complimentary addition on a blank number line to solve these additions? = = = Remember! Start on the smallest no. and jump to the largest

Expanded Method Expanded method is completed in preparation for the short efficient written method. This method is supported by apparatus such as diennes rods, place value counters and straws = T U 42

Expanded Method Expanded method extend to demonstrate the process of exchanging. This is where a ten is swapped for ten ones/units = T U

Your Turn! Can you use the expanded method to solve these subtractions? = = =

Column Subtraction Expanded method leads onto a compact efficient written method. With this method children need to be confident with place value to exchange between hundreds ad tens. T U T U H T U

Column Subtraction Rules of column subtraction: – Start with the biggest number – Align the columns H T U – Subtract from the units first – Exchange tens for units, exchange hundreds for tens T U =

Column Subtraction Once children are confident using the compact method of column subtraction for whole numbers, it progresses on to decimal amounts with money. £ £ £ p £ £ £ £ £

Your Turn! Can you use the column method to solve these subtractions? = = £ p =