Here's a hobby electronics/computers education kit that I bought a couple years ago at a yard sale for $1.It's a Science Fair kit that you wire up according to the instructions. It teaches how to understand and use commands for a little microprocessor that has some pre-programmed ROM in it. It has a small amount of RAM memory for coding in your own shtuff.
This is a video of the program for a countdown timer. On the left you can see how many minutes are left in the countdown with the 3 left-most LEDs, in binary numbers, and then the next 4 show the tens column for the remaining seconds, in binary, and the digit on the right shows the ones column for remaining seconds.
Now give yourself 1,000 Geek Points if you can read binary coded numbers!













