1. Mixing colours
I am learning to compare ratios and proportions.
3:7

2. Alice and Craig both like to make the drink ‘coke and raspberry’
Alice and Craig both like to make the drink ‘coke and raspberry’. Alice makes it by adding 2 parts raspberry for every 8 parts coke (2:8). Craig makes it by adding 5 parts raspberry for every 15 parts coke (5:15).
Whose drink will have the most raspberry taste?
Alice
Craig
You can see Craig’s ratio is made up of 20 parts and Alice’s ratio is made up of ten. To even this up we could add another ten parts to Alice’s. Obviously 2 will be raspberry and 8 will be coke.
Now let’s group the raspberry and coke together for Alice.
You can now see that Craig’s drink would have the strongest raspberry taste.

3. We could also try turning them into fractions and then finding an equivalent fraction.
Alice
2:8 or
Craig
5:15 or
We can turn Alice’s proportion ( ) into twentieths by multiplying it by two. X2
Alice:
It’s now easy to see that Craig’s drink will have the strongest raspberry taste. X2
Craig:

4. Millie wants to make green paint by mixing blue and yellow
Millie wants to make green paint by mixing blue and yellow. It is the relative amount of blue to yellow that makes the green darker.
Option A: 3 parts blue to 1 part yellow (3:1)
Option B: 8 parts blue to 4 part yellow (8:4)
Option A:
Option B:
Option ‘A’ is made up to 4 parts and Option ‘B’ is made up of 12 parts.
Let’s make Option ‘A’ three times bigger so we can compare the two options.
It’ now easy to see Option ‘A’ will make the darker green.
Now let’s group the yellow together in Option ‘A’

5. Now try these questions on your own.
Which of the blue to yellow ratios below gives the darkest green?
Click again when you have worked out all your answers.
4) 3:6 or 2:5
5) 2:3 or 3:2
6) 4:7 or 5:6
1) 2:3 or 5:9
2) 1:4 or 4:12
3) 2:2 or 1:3
Need some more practise? Try pg36 & 37 of Teacher Tools Fractions, Decimals and Percentages Book Numeracy resources