Round cake and the number pi

Students measure the circumference and diameter of cakes and fruit, then divide a cake into equal pieces.

Steps

1. Use a tape measure to measure the circumference and diameter of round objects: a cake, a plate, an orange.
2. Students divide the circumference by the diameter and compare results.
3. They work out the area of the cake and divide it into as many equal pieces as there are students.
4. Eat the cake together at 1:59 pm (3.14159…) or, if that does not fit the timetable, symbolically at 9:26.

Tip: A tart or cheesecake is easier to cut than a cream cake.

Materials needed

• Tape measure (1 per group)
• Protractor (1 per group)