A numerical digit is a basic symbol used in a numeration system. The 10 digits used in our decimal, or base-ten, numeration system are: A digit refers to the single symbol used to represent a number. In the example above, each of the symbols is an individual digit. In other words, in "365," the 3, 6, and 5, are digits, but 365 as a whole is not a digit. 365 is a numeral that represents the number three hundred and sixty five: Essentially, a number is an idea or concept of an amount, a numeral is a representation of this amount, and numerals are made up of digits. This is similar to how words work. Letters make up words the same way digits make up numerals, and words can be used to form ideas the same way numerals represent numbers. Did you know? Fingers and toes are also called digits. Perhaps the reason for a numeration system with 10 digits is that humans have 10 fingers!