Think about a rule you may know. Here it is: wear a seat belt. A seat belt helps keep a person safe and secure inside a car. Look at the numbers for a seat belt. Wearing a lap and shoulder belt reduces the risk of fatal injury by 45 percent in a car. In an SUV, van or pickup, it reduces the risk of fatal injury by 60 percent.

Safety rules say to stay out of traffic and to cross streets at crosswalks or intersections. You may have heard that rules are only there to punish people. In fact, many rules are there to keep people safe. Health groups say a rule should be explained in words a child can understand. The CDC also says to tell a child why a safety rule matters, such as staying out of traffic.

Now think about taking turns. Who gets the toy first, and for how long? Rules can answer that. Let's see how. Preschool children learn to take turns. When two children share a toy, each gets an equal turn, like five minutes each. Children can ask politely for a turn, like "May I please have it first?" Even three-year-olds can work out a toy dispute by taking turns or trading. Playing with other children helps a child learn about sharing and friendship.

What makes a good rule? Health groups say rules work best when they are clear and stay the same. A good rule is also clear and open, so everybody can know what it is. A fair law is for everyone the same. Equality before the law means no one gets special privileges.

Games have rules too. In 1891 a teacher named James Naismith invented basketball and wrote its first rules. Naismith was a teacher. He invented basketball as an indoor game to replace boring or dangerous exercises at his school. Basketball began with one teacher at one school, and its first rules were written in 1891.

Long ago, a king named Hammurabi ruled Babylon. He was a king of Babylon who ruled from 1792 to 1750 BCE. His laws were written down. They were carved on a tall stone pillar so people could see them. The pillar was found at Susa in 1901 and is now in the Louvre in Paris.

The United States Constitution begins with the words "We the People of the United States." Its Preamble lists goals for the Constitution, including to form a more perfect Union and establish justice. The Preamble says the people "ordain and establish" the Constitution for the United States of America.

The Constitution gives the power to make federal laws to Congress. Congress has a Senate and a House of Representatives. A bill has to pass both the House of Representatives and the Senate before it can become a law. Both the House and the Senate must pass a bill.

Rules were being written down in England too. In 1215, King John of England granted Magna Carta, a charter of liberties, to his barons. King John was the king, and the barons were the people he granted it to.

Let us go back over the rules we met, one by one. A seat belt helps keep a person safe and secure inside a car. When two children share a toy, each gets an equal turn, like five minutes each. A fair law is for everyone the same. Hammurabi's laws were carved on a tall stone pillar. The Preamble lists goals for the Constitution. And a bill has to pass both the House of Representatives and the Senate before it can become a law.

Words to know

• Preamble: list of goals
• Congress: Senate and House
• pillar: tall stone
• equality: same for all