Written Calculation: Subtraction leads pupils through the necessary steps for mastering the column method of subtraction. Pupils beginning this book should have an understanding of the value of digits in two- and three-digit numbers, experience of adding and subtracting single-digit numbers and know their subtraction number bonds to 20.

Each of the 18 steps features the following sections.

• What to do – detailed explanations and a worked example.
• Now you try – questions that are similar to those in the worked example.
• More practice – questions that are more difficult and provide less support than those in Now you try.
  Problem solving – word problems.
• Self-evaluation rating – to help identify pupils who may be struggling with the step.