Equipment: An A4 sheet of paper.

Demontrtae that when I fold the paper in half, I halve the surface area and double the thickness (height).

Do this say 6 times (and it will be getting difficult to fold.)

Q: Imagine that I could carry on folding this sheet of A4 paper in half 39 times. How tall would the paper tower be?

Explain you're not looking for exact numbers just order of magnitude....eg as tall as this table, this ceiling, this house etc.

The surprising answer is that it would reach the moon!

Jules Vern

How can that be? Well, the moon is 252,088 miles from Earth and a piece of paper of (0.1 cm) thick folded 39 times exponentially would be 54,975,581,389 cm thick, which equals to 341,602 miles, which would not only reach the moon but well beyond it!

But pause for a moment as the more amazing fact is that on the 38th fold it would only be 68% of the way there and on the 37th fold only 34%! Pretty incredible, isn't it? But that's the power of an exponential, that it lets you turn small things into huge things by simply compounding what you have, over and over, again.

And incredibly, it only takes 39 folds of a paper to get from the Earth to the Moon, and only about 94 folds of a paper to make something the size of the entire visible Universe! And how surprised are you that the answer is so small a number? This is exponential power!