Stage 6: Column Method
Most children should be secure in this method by the end of Year 4. Through use of the apparatus and supported column method procedure, children will become confident to record just the written calculation in column format. Earlier use of concrete apparatus reinforces the understanding of where the regrouped tens or units have originated from. By the end of year 5 children should extend this method to subtraction of any number of digits.
Column subtraction remains efficient when used with larger whole numbers and decimals. Once learned, the method is quick and reliable.