Today we made solar ovens using empty Graze boxes. Saved having to go to Pizza Hut!
We cut a flap in the lid and covered it with silver foil.
The window that was made was covered in a couple of layers of cling film.
We put black paper on the inside.
Then we put our chocolate buttons on the inside and took the ovens out into the sun. Sadly, it was cloudy and so no melting occurred, but we did get melting when using a lamp instead of the sun.