Children solve problems effortlessly, their ideas may often be impractical but they produce them with a fluency, zest and irrepressible imagination that ought to be the envy of many an adult and especially those who are paid to solve difficult problems. Nevertheless it is primarily as an insight into the processes of the mind that this book offers a collection of children's thinking. The nine tasks the children where set included, devising a machine to weigh elephants, a system for building a house quickly, a sleep machine, a space rocket, improvements to the human body and methods of helping the police deal with bad men. Each task was carefully chosen to involve the children in coping with problems of a distinct character.