A kid bought stuff worth Rs 45 from Santa's shop and gave him a 5 rupee note and put '0' (zero) behind 5 and gave it to Santa.
On top of it, he asked for the balance Rs 5.
Having been outsmarted, Santa took out a 50 rupee note and crossed '0' (zero) with a pen and gave it to the kid and said, "Now we are even"!