In baking a hemispherical loaf of bread of 10" radius, the crust was everywhere of an equal thickness, and the solidity of the crust was equal to half the solid content of the whole loaf. What were the dimensions of the interior soft part?
Where does pi come from? Why should we be interested in negative numbers, or square roots of negative numbers? How did people ever figure out the quadratic formula? A truly wonderful reference for teachers at all levels.