Ratio Murder Mystery | KS3 & GCSE Foundation Maths Problem-Solving Activity

Make ratio revision meaningful and engaging with this Ratio Murder Mystery, suitable for Grades 5–7, KS3 Maths, and GCSE Foundation. Students become detectives as they work through four sets of ratio questions to uncover the weapon, the killer, the time of the murder, and the location. This activity transforms routine ratio practice into a high-engagement challenge that encourages problem solving, reasoning, and careful thinking.
This resource is ideal for revision lessons, independent work, group tasks, or an end-of-topic challenge. It works particularly well with mixed-ability groups and reluctant learners who benefit from a structured, story-based activity.

What’s Included
• Full student murder mystery worksheet
• Four clue sections linked to:
– Simplifying ratios
– Finding missing values in equivalent ratios
– Ratio word problems
– Comparing ratios
• Final deduction activity to identify weapon, killer, time and location
• Complete answer sheet for quick marking
• Suitable for classwork, homework or cover lessons

Activity Overview
Dr Rachel Numbers has been murdered at Ratio Mansion. Students must solve a sequence of ratio puzzles in order to eliminate suspects and uncover the key details of the crime. Each set of answers reveals a new part of the mystery, encouraging learners to work accurately and logically.

Sample Questions
Below are examples of the types of questions included in the full activity:
• There are 12 red marbles and 16 blue marbles. Write the ratio of red to blue in its simplest form.
• 3:5 = 9:__. Find the missing number.
• A school has 60 students. The ratio of boys to girls is 3:2. How many boys are there?
• Are the ratios 3:4 and 9:12 equivalent? Explain your answer.
Students use these answers to unlock clues that lead them to the final solution.

Perfect For
• KS3 Maths
• GCSE Foundation ratio revision
• Grades 5–7 learners
• Group work and problem-solving lessons
• Revision sessions
• Cover lessons
• End-of-topic consolidation

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