Kitchen roll and number bonds

If you make kitchen towel wet, you can see through it i.e. it becomes translucent and light can pass through rather than being reflected off the surface. Hidden drawings underneath become visible. I used this to liven up a bit of maths, giving my son a fun way to practice number bonds (i.e. pairs of numbers that add) to 10.

I folded sheets of kitchen roll in half, and drew - with permanent pen - a circle with 10 inside, then two circles to represent the parts it can split into, one with a number and one blank. This leaves an outline on the other side of the kitchen paper and you can then add the number that is missing on the back part of the folded paper so it sits underneath the blank circle. If you add a little water on top, or float it on a tub of water, the missing number becomes visible! 

Number 7 is written on the layer behind

I set my son up with his Numicon to help him work out what the missing numbers are, and explained that he needed to tell me what number should be in the circle. Then I asked him to add a little water on the empty circle with a pipette to reveal the answer. 

Revealing the hidden 7

He loved it, and we did all the number bonds to 10. He guessed most of the answers and checked he was correct with the Numicon (if you stack the number piece that's in one small circle on the 10 shape you can see which number shape is needed to cover the rest of the 10) before putting water on. 

3 + 7 = 10

This was definitely an engaging way to give him some practice with number bonds to 10.  I'm sure there are other activities that we could use this approach for in future too.