Mental Addition

Revision of adding several small numbers mentally, using strategies learned earlier.

These are about as hard as you will get for mental arithmetic. Many children (and adults) will find them very tricky!

Adding two 3-digit numbers mentally. Often it is best to start with the hundreds, then the tens and finally the units; this is the opposite order than when using written methods.

Further practice with mental addition using a variety of strategies to answer them quickly and correctly.

Mental addition skills with numbers up to 3 decimal places.

Work out mentally the answers to these sets of addition sums. For some, write down the method used to do it.

Without any written working out, answer these addition and subtraction of multiples of 100.

Completing addition sentences using mental methods.