Rules are part of every day. Some keep people safe. Some help people share. Some make a game work. Let us look at why they are there.

Start with a car. A seat belt helps keep a person safe and secure inside it. The numbers show how much. A lap and shoulder belt cuts the risk of dying in a crash by 45 percent in a car. In an SUV, van or pickup it cuts the risk by 60 percent.

Streets have safety rules too. People are told to stay out of traffic. They are told to cross at crosswalks or intersections. You may think rules are only there to punish. In fact, many rules keep people safe.

Health groups say rules work best when they are clear and stay the same. They also say a rule should be explained in words a child can understand. The CDC says to tell a child why a rule matters, such as staying out of traffic.

Rules also help people share. When two children share a toy, each gets an equal turn, like five minutes each. Children can ask in a polite way, such as, May I please have it first?

Even three-year-olds can work out a toy fight. They can take turns or trade. Playing with other children helps a child learn about sharing and friendship. Preschool children learn to take turns.

Games need rules. In 1891, a teacher named James Naismith made up basketball and wrote its first rules. He wanted an indoor game to replace boring or dangerous exercises at his school.

People wrote down rules long ago. Hammurabi was a king of Babylon who ruled from 1792 to 1750 BCE. His laws were written down.

A good rule is clear and open, so everybody can know what it is. A fair law is for everyone the same. That idea is called equality before the law. It means no one gets special privileges.

Words to know

• intersections: where roads cross
• equal: the same
• privileges: special perks
• Babylon: an old place
• polite: kind in manner