How to subtract numbers
To subtract numbers from each other you can use a variety of written methods such as the column method, or a number line; or you could use a mental arithmetic method.
Resources for physically subtracting numbers together could include: an abacus, a 1000 square, Cuisinaire rods, Numicon, Base 10 or simply use cubes or counters.
Try using more than one method and practice checking your answers with a calculator.
Government guidelines (Year 3) Pupils should be taught to:

Subtraction worksheets  Year 3 Primary maths resources, activities and worksheets
Copyright 2010. All rights reserved
Subtracting from numbers, up to 1000