ANYTHING TIMES 0 IS ZERO
EX.
If I have a dollar in my hand and multiply it by 0, won't I still have a dollar? If not, then who took my dollar?
Let's fix your picture to make it clear where money is coming from. Let's say you're a barber and every customer tips you a dollar. At the end of the day, how much have you made in tips? Multiply a dollar by the number of customers you had. If you had 10 customers, you made $10. If you had 20 customers, you made $20. So, what about the day that your shop was closed because of a blizzard? By your reasoning, you'd still make a buck, even though you had zero customers. No, it's clear that you make $0: $1 times 0 customers is $0.
