The domino is an intriguing, yet surprisingly simple toy that has stood the test of time. Many children have played with dominoes, often making lines of them or constructing structures like towers and pyramids. More recently, however, it has become fashionable to create and display works of art using dominoes. The artist Hevesh has created mind-blowing domino setups for movies, TV shows, and events, including a recent album release for Katy Perry. Hevesh’s creations can take several nail-biting minutes to fall, as the dominoes follow their own path based on the laws of physics.

Dominoes are small rectangular blocks of wood or plastic, each bearing from one to six pips or dots (see domino). A set contains 28 such pieces. Each piece has a different number of pips on each face, and the pips are used to identify each domino’s value or rank. Dominoes are also used to play games in which players try to place dominoes edge to edge, so that the values on adjacent sides match or form a specific total. Dominoes can be arranged in straight or curved lines and even 3D shapes.

Aside from the traditional blocking and scoring games, some dominoes have unique characteristics that make them particularly useful for educational purposes. For example, some dominoes have a grid pattern that makes them suitable for use in math games where students can count the pips on multiple tiles simultaneously. Other dominoes can be used to teach the difference between positive and negative numbers. Still others can help students practice counting and number recognition skills. In addition, dominoes can provide an interesting way to introduce the concept of probability.

The most common dominoes are made of ivory, silver lip ocean pearl oyster shell (mother of pearl), or a dark hardwood such as ebony, with black or white pips inlaid or painted. Some sets are made of natural materials other than these, such as stone (e.g., marble or granite); other woods (e.g., spruce or pine); metals (e.g., brass or pewter); and ceramic clay.

The most commonly used dominoes are double-six pips, but many different types of pips are available in “extended” sets. In such extended sets, the pips on each domino are increased from two to three or more. This allows the possibility of more matches between end-to-end pairs of tiles and increases the number of possible game variations. As the number of possible combinations grows, identifying individual dominoes becomes more difficult. To make this easier, some larger domino sets use more readable Arabic numerals in place of the traditional pips. Dominoes may also be printed on a polymer material such as plastic. This type of domino is more durable than wooden dominoes and is less likely to chip or scratch, but it is not as aesthetically pleasing.