The Power of Compounding

My favourite story from Doraemon was a story about a Bank introduced to Nobita, Doraemon said the interest is 10% per hour. If Nobita saves 10 yen and leave it for a week, 10 yen becomes 89million.
My little brain of a 8 year old could not get my head around this number. It seems absurd. So I took a calculator, pressed 10*1.1, and press equals 168 times. I repeat this process several times until I am certain Doraemon did not made a mistake with his numbers.
That is the first time I discover how powerful compounding is...