6b. proportion

Proportion

Created by Richard Bull

If the amount of green, increases then so must the red. And by the same amount

The amount of green has double from 1 to 2, so the amount of red has doubled as well. This is called direct proportion

To paint 1 wall

To paint 3 walls?

As a ratio is

2 : 4

Is this proportional?

To this

4 : 6

So is 2:4 proportional to 4:6

Here is how to check

6

Multiply the diagonals, and then divide by the other number

3

2 : 4

:

The number you get is 3, not 4. So no

2:4 and 4:6 are not proportional

2 x 6 ÷ 4 =

You buy 5 litres of paint for £3.20and 10 litres of paint for £6.30

Is this proportional? Show your working

It cost you £55.50 for 10 t-shirts, what is the cost of 3 t-shirts

You could use the method of finding the price of 1 t-shirt first:

So £55.50 ÷ 10 = £5.55

Then £5.55 x 3 = £16.50

Can be used for proportion and other

useful calculations.

Cross multiplication

NHS England

July 5 1948 – The NHS is born

• Since its launch in 1948, the NHS has grown to become the world’s largest publicly funded health service. It is also one of the most efficient, most egalitarian and most comprehensive.

• The NHS was born out of a long-held ideal that good healthcare should be available to all, regardless of wealth – a principle that remains at its core.

• This section gives an overview of the changes and milestones of the NHS in England from its launch in 1948 to the present day.

Example: there are roughly 9 nurses and

midwives for every 1,000 people in the UK

This can be written as 9 : 1,000

This is called a ratio, or a conversion ratio

So:

If a question were to ask if there are 9 nurses and midwives for

every 1,000 people in the UK, how many nurses and midwives

would there be for 35,000 people?

Some people may be able to answer this already, BUT!

I want you to use my method!

Step 1

Write down the conversion ratio for

nurses to people

9 : 1,000

Nurses People

Label the numbers

Step 2

Underneath the conversion ratio input the

new figure, in this case it is 35,000 people

9 : 1,000

Nurses People

35,000

Multiply the diagonals, and then divide by the other number

315

Created by Richard Bull