Year 5 pairs write 'Which rectangle am I?' riddles whose clues must leave exactly one answer. The teacher models the problem first: 'My sides are whole centimetres and my area is 36 cm²' fits five rectangles, from 1 by 36 to 6 by 6, and adding 'my perimeter is 30 cm' leaves only 3 cm by 12 cm. Each pair writes three riddles of their own, such as 'My perimeter is 26 cm and my area is 40 cm²' for 5 cm by 8 cm, and tests each in their books by listing every rectangle that fits the clues. They type the riddles as posts on a class Padlet wall, set to school login with author names hidden, with posts approved by the teacher and signed with a table number. The other Year 5 class does the same on a wall of its own, and for the last twenty minutes the classes swap walls, solve each other's riddles and add their answers as comments. Authors then read every comment under their riddles, reply to say which are right and, where a solver has found a second rectangle that fits, write in their books the clue that would have ruled it out.
This page is one of a growing set of PICRAT examples by cell, subject and grade. Page maintained by Andy Perryer.