Answer:
Jackson owes his sister Monica $15. Monica has a $10 bill in her pocket.
We only have one zero, here which is in $10.
We can say that the zero is the place holder for showing the value of 1. 1 with 0 makes 10 dollars.
If there was no zero, then Monica would have only $1 in her pocket.
But by adding a 0 in the one's place and shifting the 1 to tens place, we get a value of 10.
