Binary number through each symbol, in increasing order. Before examining binary counting, it is useful to briefly discuss the more familiar decimal counting system as a frame of reference. Decimal counting uses the ten symbols "0" through "9". Counting begins with the incremental substitution of the least significant digit (rightmost digit) which is often called the "first digit". When the available symbols for this position are exhausted, the least significant digit is reset to "0", and the next digit of higher significance (one position to the left) is incremented ("overflow"), and incremental substitution of the low-order digit resumes. This method of reset
Computer number format sixteen values, a nibble is sometimes known as a hexadecimal digit. Octal and hex are convenient ways to represent binary numbers, as used by computers. Computer engineers often need to write out binary quantities, but in practice writing out a binary number such as 1001001101010001 is tedious and prone to errors. Therefore, binary quantities are written in a base-8, or "octal", or, much more commonly, a base-16, "hexadecimal" or "hex", number format. In the decimal system, there are 10 digits, 0 through 9, which combine to form numbers. In an octal system, there are only 8 digits, 0 through 7.