Efficient Subtraction Higher

The purpose of this worksheet is to encourage children to make choices about which method is most appropriate for a given calculation.

Children can often become reliant on formal written methods, so it is important to explicitly highlight

where mental strategies or less formal jottings can be more efficient.

Children explore the concept of constant difference, where

adding or subtracting the same amount to/from both numbers

in a subtraction means that the difference remains the same,

for example 3,835 – 2,999 = 3,835 – 3,000 or 700 – 293 = 699 – 292.

This can help make potentially tricky subtractions with multiple

exchanges much simpler, sometimes even becoming calculations

that can be performed mentally.