Number tree

My son loves numbers and this helped him connect the written number to the amount it represents.

The top part of the enclosure has recessed numbers, I printed it with filament swapping to get a few layers of red, but you can paint it if you like.

I did a minimal effort on the electronics and built logic gates with diodes, making it only possible to light up one entire row at the time. That's good enough for it's intention, but should you want to add some effects it wouldn't be too difficult to add a little MCU. 

The enclosed schematic gives 16mA per LED with a 4.2V lithium cell (At 4.2V …). Adjust the resistor values if you use another type of battery.

You will need:

• 1 x top enclosure print
• 1 x lid print
• 10 x light dome print
• 1 x countersunk M3 screw
• 10 x 3mm LEDs
• 10 x 12x12 mm push buttons
• 20 x diodes
• 10 x 110 Ohm resistors
• Battery and holder

Glue the light domes in the enclosure, I let the LEDs sit with just friction fit.

Then wire everything up according to schematic. To save my dignity I'm not going to show any images of my wiring job. (Note the varying intensity of the LEDs in the cover photos, that's not due to differences in the LEDs)

I used buttons like these https://www.aliexpress.com/item/1005004522150256.html and a generic battery holder with an 18650 cell. Absolute overkill in terms of power, but I had one right next to me when making it :)

Here is the OnShape source if you want to modify it for different buttons etc.

https://cad.onshape.com/documents/02938e948057cf8a627386e2/w/9ce5c9738d27b27aec98d342/e/e951ecc07d8ba1e5e3ed2ba7?renderMode=0&uiState=63dcd0a6eee4a7745fb50c31