I tried to make some binary to decimal decoders, but I had no idea how to build them, so I ended up using the "combination checker" (basically providing one checker for each number). That was really inefficent and almost impossible when decoding e. g. 32-bit numbers (4,294,967,295 combinations). So I want to ask, is there some logic pattern you build over and over? Or should I make a separate arithmetic unit for calculating  this the mathematical way? Thanks for help