What process is used to convert numbers between the binary system and the decimal system? Enter the number in a calculator, divide by 2, and multiply by 10. Convert each binary number to a letter, then use the letter’s place in the alphabet as the decimal representation ( e. g., A = 1, B = 2). Add up the digits in the binary number and place the sum behind a decimal point. Look up the number on a binary-to-decimal conversion table.