1
Set up the ratio equation
2
Find what one side was multiplied by
3
Apply same multiplication to other side
4
Example: If 3:5 = 12:?, then 3Ć4=12, so 5Ć4=20
This deep dive covers Method: Finding Missing Values within Ratio Basics for GCSE Mathematics. Revise Ratio Basics in Number for GCSE Mathematics with 12 exam-style questions and 22 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 5 of 15 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Ratio Basics
Write the ratio 12:18 in its simplest form.
Explain the difference between the ratio 3:5 and the ratio 5:3.
Quick recall flashcards
Order in Ratios
Order MATTERS!
Boys:Girls = 3:5 means:
ā¢ 3 boys for every 5 girls
Girls:Boys = 5:3 means:
ā¢ 5 girls for every 3 boys
Different meanings!
What is a ratio?
A comparison of quantities of the same kind
Written as a:b or a/b
Example: 3:5 means '3 parts to 5 parts'