The dual system, also known as the binary system, is a base-2 number system with only two elements, 0 and 1. The conversion of multi- digit decimal numbers into dual numbers results in long columns of numbers consisting of zeros and ones, since the entire decimal number is converted and not each individual digit of a decimal number.
For example, the one-digit decimal number 9 becomes the dual number 1001, according to the place value system 8-4-2-1. The two-digit decimal number 43 becomes the dual number 1010011 according to the valence 32-16-8-4-2-1. The three-digit decimal number 146 becomes the dual number 10010010 with the valence 128-64-32-16-8-4-2-1.
To avoid these long columns of numbers, various binary codes have been introduced that work with bit groups of four bits. The most commonly used system is the hexadecimal system, which uses four bits and has base 16, or the octal system with three bits and base 8.