Multiply means to increase a number by adding it to itself a certain number of times. When you multiply 4 by 3, you're adding 4 three times: 4 + 4 + 4 = 12. Multiplication is one of the core operations in math, along with addition, subtraction, and division.

Learning to multiply opens up huge possibilities in mathematics. Without multiplication, calculating the area of a rectangle would be tedious (imagine adding the length to itself over and over for each row). Multiplication makes these calculations fast and efficient. When you multiply 7 by 8, you get 56 in seconds, rather than counting by 7 eight different times.

The word also means to increase greatly in number or amount. Bacteria multiply rapidly under the right conditions, doubling every few minutes. Problems can multiply when one mistake leads to several others. When rabbit populations multiply in an area with no predators, their numbers can grow from dozens to thousands in just a few seasons.

The symbol for multiplication is ×, though programmers often use * instead. The numbers being multiplied are called factors, and the result is called the product.