This document discusses different number systems including decimal, binary, and hexadecimal. It provides steps for converting between these number systems. Decimal to binary conversion is done using successive division by 2. Binary to decimal conversion multiplies each bit by its place value and sums the results. Binary to hexadecimal breaks the binary number into groups of 4 bits and maps each group to a hexadecimal digit. Hexadecimal to binary does the reverse. Decimal to hexadecimal converts each decimal digit to its hexadecimal equivalent. Hexadecimal to decimal multiplies each digit by its place value and sums the results.