A few weeks after a fractions unit, someone will still tell you 1/8 is bigger than 1/4. This revisit is built around a shared block of chocolate, opening with the wrapper and its nutrition panel. Students revisit number lines and the fraction wall, then add and subtract, find fractions of amounts and work with percentages and discounts.

How it runs

Four lessons of 45–60 minutes, with a pre-test first. Lesson 1 is number lines and the fraction wall. Lesson 2 uses proper and improper fractions, 10 cm fraction bars and related denominators. Lesson 3 is same-denominator adding and subtracting, the complement principle and related-denominator word problems. Amira writes 1 − 1/5 = 0/5 "because 1 − 1 = 0", and students explain her mistake. Lesson 4 covers building the whole from a part, fractions of amounts and percentages, with a bookshop discount, a savings task and the Case of the Missing Chocolate.

Maths covered

• MA3-RQF-01: order fractions on number lines and fraction walls, compare related denominators, and add and subtract fractions where the result may be greater than 1
• MA3-RQF-02: find fractions of amounts with tape diagrams, build the whole from a part and find 1/2, 1/4, 1/5 and 1/10 of collections with remainders as decimals
• MA3-RN-03: link 50%, 25%, 75% and 10% to fractions and decimals and calculate 10%, 25% and 50% discounts
• Extension (Stage 4): adding fractions with unrelated denominators (and twelfths) appears only in a clearly labelled box and slide (MA4-FRC-C-01)

Good to know

• The fraction bars measure exactly 10 cm when the booklet is printed at 100% (actual size).
• A real 24-square chocolate block (or paper squares) suits the case file.
• Refreshed from my 2021 Fraction Revisit PowerPoint. Maths Detectives characters and Keynote fonts included.