# Number - Multiplication and Division

## Multiplication

Feed the monster with your multiplication tables knowledge and help it to evolve... Try out Purplemash's new game. You can find it by logging into your Purplemash account --> Mathematics --> Times Tables --> Monster Multiplication

Purplemash has another excellent tool too - ideal for helping you recall a particular multiplication table.

With Table Toons you can create a catchy tune to aid your memory!  The example below will give you an idea.

Log into your Purplemash account --> Mathematics --> Times Tables --> 2Simple Table Toons

## Factors

Recognise and use factor pairs and commutativity in mental calculation (a Year 4 objective, but used by Year 3 too!)

Factors are numbers that divide exactly into another number.

For example, the factors of 8 are:

1, 2, 4, 8

because

1 x 8 = 8

8 x 1 = 8

2 x 4 = 8

4 x 2 = 8

You will notice that 8 x 1 and 1 x 8 and the same thing (this is because they are commutative – which means that you can change the order of the numbers but the answer will still be the same).

To make things a bit simpler factors can be shown in pairs. In this case each pair multiplies to make 8.

The factor pairs of 8 can be shown as:

1 x 8 = 8

2 x 4 = 8

An excellent way of testing your understanding of factors (and your multiplication knowledge) is with the Purplemash game Factoroids. Log into Purplemash --> Mathematics --> Games to find it.

You might also be interested in this BBC Bitesize video and task.

Confident?   Why not try these factors problems. You could either write them in your book or print them if you prefer.

(HINT: If you're finding some of them a little tricky your times table book might help)

Still not too sure?   Or perhaps you're very confident?   Either way you might want to try some further factors.

Write down all of the factors that you can find for the numbers in the document below.   Good luck!

## Division

Progressing to the formal written method for division

If numbers are too difficult to divide in your head then use a written method. Short division will sometimes give an answer with a remainder (r). You can remind yourself of short division with this BBC Bitesize video:

To find the answer to 365 ÷ 7 see if 3 (the hundreds) can be divided by 7.

It cannot, so add the tens digit. 36 ÷ 7 = 5 r 1.

Write down the 5 and carry over the 1 so 5 becomes 15.

15 ÷ 7 = 2 r 1.

Write those numbers down. The answer is 52 r 1.

Remainders can be a little tricky to remember. Luckily BBC Bitesize are here to help you once more (this time, aided by a pirate!). You can find the video here.

TASK: The Ancient Egyptians have got into a terrible muddle with Division. Can you help them? Try the questions below.

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