Catch the eight
Electronic
7400, 7476

Here's another IC and display game to test your wits. In this project, you won't be "shooting" at LEDs... instead, you'll be trying to catch an eight!

Once you finish wiring, turn power ON. Then set the slide switch S1 to ON. On the LED display you'll see the upper and lower parts of "8" are flashing alternately. Now carefully note the pattern of flashing. You'll note there's a moment when the display shows nothing - when you think you can anticipate the moment of no display, slide S1 to OFF.

If you do it at exactly the right moment, a complete 8 is "captured" and flash over and over on the LED display. If you don't - well, slide S1 to ON and try again.