100 bills, Jerry.
Jerry: " BUT WHY? "
Excellent question, Jerry, you forward thinker.
Well....
10x1=10
10x10=100
See how the product has the same number of zeros as the actual problem?
Look:
10x100 has 3 zeros.
The product is 1,000, which ALSO has 3 zeros.
So, to save yourself the trouble, just count the zeros.
Jerry: " WOW I GET IT NOW!"
AND SO SHOULD YOU AFTER READING THIS! :)