Revision of adding several small numbers mentally, using strategies learned earlier.
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.
These are about as hard as you will get for mental arithmetic. Many children (and adults) will find them very tricky!
Further practice with mental addition using a variety of strategies to answer them quickly and correctly.
Without any written working out, answer these addition and subtraction of multiples of 100.
Tricky sums, these. Think about the digits in the tenths and hundredths columns when working out these addition of decimals questions.
Work out mentally the answers to these sets of addition sums. For some, write down the method used to do it.
When adding using decimals it is very important that the decimal points should line up under each other. If the sum also involves whole numbers it is a good idea to put a decimal point after the whole number followed by a zero.