This document describes how to convert a Binary Coded Decimal (BCD) number to its equivalent binary number. It explains that BCD represents decimal numbers as 4-bit binary codes, with values 0-9 having their own codes. For values above 9, each decimal digit is represented by a 4-bit code. The document includes a truth table and Karnaugh maps to derive the logic gates needed for a BCD to binary converter circuit. It also notes that for BCD values above 9, the most significant bits in the binary output are "don't cares".