The natural world comes alive for young readers with Rookie Read-About Science! Rookie Read-About Physical Science series introduces the youngest readers (Ages 6-7) to physical science concepts. Each book features critical-thinking questions throughout the text; a simple, hands-on experiment; a glossary and more.
This explains how a balance works. Its examples are a little outdated now. Jewelers using a balance scale and taking your weight at the hospital with a balance scale have dated the book. Otherwise it does explain the concept well.