Binary to BCD converter

Hey folks. I need to create a binary to BCD converter using a mux and a demux (encoder and a decoder), but I have no idea what to do. Normally, I catch on quickly in digital, but I'm very sick right now, and can't really think for myself. Can anyone point me to a diagram or explain the concept of how it's done to me so I can breadboard it for tomorrow?
Thanks in advance.

In TTL series 74184 and 74185 existiert, maybe You can find it.

74185 no longer are being sold, as far as I know; plus, I have to do it with the encoder and the decoder, and without using a microcontroller and assmebly (that would have been easy).