Semicircles are drawn on the sides of a rectangle. Prove that the sum of the areas of the four crescents is equal to the area of the rectangle.
What happens when you add three numbers together? Will your answer be odd or even? How do you know?
This activity is best done with a whole class or in a large group. Can you match the cards? What happens when you add pairs of the numbers together?
Tony and Tina can't work out which of them owes what to the other. Can you?
Florence, Ethan and Alma have each added together two 'next-door' numbers. What is the same about their answers?
Weekly Problem 9 - 2006
What fraction of the area of the rectangle is shaded?
Can you prove that in every tetrahedron there is a vertex where the three edges meeting at that vertex have lengths which could be the sides of a triangle?
