Level 1 - Identifying ratios from pictures
Level 2 - Simplifying ratios
Level 3 - Simplifying ratios with mixed units
Level 4 - Reducing a ratio to the form 1:n or n:1
Level 5 - Simplifying ratios with fractional parts
Level 6 - Dividing a quantity in a given ratio
Level 7 - Comparing the parts of a ratio
Level 8 - Using ratios in real life