- In the base-10 numbering system, a digit is a symbol represented by a 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9
- A number is formed by a single digit or several digits
- Example: 425 is formed by 3 digits, 4, 2, and 5
- Each digit in a number has a place value that depends on the place or position it occupies in the number
- The sum of the place values of the digits in a number equals the value of the number