Search Results For “doubling and halving to 20”

Use a number line to count on and back across zero.

Revision pages on adding to make multiples of 10 and subtraction of multiples of 10.

Addition and subtraction of multiples of 100. Easy if you know the totals of pairs of single digits.

Work out the addition questions in your head and just write down the answers.

Revising adding and using the relationship between addition and subtraction.

Mental addition and subtraction using decimals to make a total of 1 or 10.

Applying knowledge to add and subtract decimals mentally.

Adding and subtracting numbers that cross the thousands boundary: often ?counting on? is the best method.

Add twenty and take one is much quicker than trying to add nineteen. But not always!

Use the numbers in the octagon to create and answer subtraction questions using multiples of 10 and decimals.

Remember to move the digits two places to the right to divide by 100.

We return to an important concept again: the relationship between multiplication and division.