Dominoes are small rectangular blocks of wood or polymer material with either black or white dots. They are normally twice as long as they are wide and can be stacked on end to form long lines. When a domino is tipped over, it causes the rest of the line to tip over, resulting in a chain reaction that can continue until all the pieces have fallen over. These toys are popular among children, but adults can also play with them. The most common type of domino set contains 28 individual dominoes that can be used for a variety of games. They are also known as bones, cards, men, tiles, stones, spinners, or tickets.

When a player takes his turn, he must first lay down a domino whose two sides match the number of dots on each other or a specified total value such as three to five or six to nine. He may then add to the dominoes in his hand by placing one on top of another in a way that makes the new piece form a square with the old one or adds to its total value. Depending on the game, he may then add more dominoes to his hand or be required to play all of them before taking another turn.

Aside from the aforementioned positional games, dominoes can be used for other types of play, including free-play, where players simply try to place their dominoes on a table in such a way that they are all touching or that their total value equals some figure such as seven to thirteen or fifty-one. Other games require that a player take turns in the same manner but with the goal of removing all of his or her own dominoes from the table. Traditionally, dominoes have been used on flat surfaces such as tables or the floor, although many people enjoy playing them in vehicles such as cars, trains, or airplanes.

In addition to being a fun family activity, domino can help improve a child’s mathematical skills. For example, a teacher can have students hold up the first domino in a line and ask them how many dots it has on each end. Then the teacher can demonstrate how to find the sum of all the numbers on the domino’s two sides, such as 4+2=6. Students can then use the information to build their own addition equations and see how they compare to the original.

The name domino itself likely comes from an earlier sense of the word to denote a long, hooded cloak worn in conjunction with a mask at carnival time or a masquerade. The word also appears in some English-language documents from the 17th century. In Italian, domino is also the name of a game played with a large tile. The game was introduced to England and France in the mid-18th century, while the word itself remained in French until shortly after 1750 when it became the basis for the English version of the game.