Simple machines : wheels, levers, and pulleys / by David A. Adler ; illustrated by Anna Raff.
Kids use simple machines every day without realizing it. Teeth are wedges and so are knives, forks, and thumbtacks. Many toys such as slides, which are inclined planes, and seesaws, which are levers, are also simple machines. Two appealing kids and their comical cat introduce levers, wheels, pulleys...
New York :
Walker Library - Curriculum Collection - Juvenile - 3rd Floor
Pull and Hold