This puzzle is almost four thousand years old. It was invented by the ancient Egyptians and recorded by the scribe Ahmes in 1650 BC. Use the space below to find the solution to this puzzle.

A wealthy Egyptian farmer owned seven barns. Each of the barns housed seven cats. Each of the cats caught seven mice. Each of the mice would have eaten seven sheaves of wheat. Each sheaf of wheat produced seven measures of flour. How many measures of flour did the farmer's cats save?