A digit is a single symbol used to represent numbers. In the most common decimal system (base 10), digits are the symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. These digits can be used alone or in combination to form numerals that represent numbers. For example, the numeral "15" is made up of the digits 1 and 5. Digits are the basic building blocks of numbers in positional numeral systems, where the value of a digit depends on its position in the sequence. For example, in the number 312, the digit 3 represents three hundreds, the digit 1 represents one ten, and the digit 2 represents two units. Aside from the mathematical meaning, the word "digit" can also mean a finger or toe on a limb in anatomy, but in the context of numbers, it specifically refers to these numeric symbols.