Aardappelklok

My nephew was so fascinated watching the LED numbers light up from a potato that he immediately grabbed an apple to test next. The instructions are clear enough for an eight-year-old to follow mostly on his own.

We set up the potato clock on a rainy Sunday and were genuinely surprised how fast the digital display lit up. Swapping in lemons kept it running just as well, and it's been a great way to get the kids asking why it works.

My kids fought over which vegetable to test first, so we did a lemon and an apple before settling on the potato. The clock flickered to life in under a minute once we pushed the zinc and copper strips in far enough, and it’s been running steady for two days now.