If you follow me on instagram, you will have seen the fun little adding machine my daughter and I made together. We made it out of the postage box her Alice & Ames dress in. I've totally not been paid or given anything to say this but best. dress. ever.
So when Alice & Ames asked if I would write up a tutorial for how to make the "machine" I was very happy to oblige.
You can find the full tutorial here.
PS if you like playful math don't forget to check out Games for Good raising funds for UNICEF