6. Ratio
Simplifying a ratio
In our lessons we looked at how to simplify a ratio. Just like we simplify a fraction, the aim is to:
1. Identify the Highest Common Factor (HCF) What times table are they both in?
2. Divide both numbers in the ratio by the HCF.
3. Check you can’t simplify any further.
Sharing a total into a ratio
In our lessons we learnt how a ratio is VERY similar and linked to understanding fractions. A common question type asks us to share a total into a given ratio.
1. Add the numbers in the ratio together
2. Write the number you get in part 1 as the denominator in the fraction.
3. Find the fraction of the amount for each.
Given one value in a ratio
In this final ratio question type, you are told the ratio and given one value. You then have to work out what the missing value is.
1. Read the ratio and identify the which number relates to a catagory (eg. White socks to black socks means that the number 1 – in the ratio 1:3 -relates to white socks and the number 3 relates to black socks.)
2. Identify which number you have been given and which number is missing. (eg. we have been given white socks in question 1, black socks is the missing value)
3. Ask yourself how the number given has been scaled from the number in the ratio (eg. 1 – 12 has been multiplied by 12)
4. Do the same to the other number in the ratio (eg. 3 x 12 = 36)
