This study notes covers Worked Example 5: Converting Units 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 11 of 15 in this topic. Use this study notes to connect the idea to the wider topic before moving on to questions and flashcards.
Worked Example 5: Converting Units
Express the ratio 2km : 500m in its simplest form
Solution
Convert to same units:
2km = 2000m
Ratio = 2000 : 500
Divide by HCF(2000, 500) = 500
2000 ÷ 500 : 500 ÷ 500 = 4 : 1
Answer: 4:1
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:
• 3 boys for every 5 girls
Girls:Boys = 5:3 means:
• 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'