So if we know that 7 gallons of water goes through the pipe every hour, and we want to find how much water goes through the pipe after 9, we want to say,
7 gallons of water 9 times because there are 9 hours.
7 gallons of water 9 times is basically 7 * 9, or 63.
So 63 gallons of water has moved through the crack after 9 hours.
