Residential water meters usually have 7 digits, and the last one is a stationary zero (0). The last digit recorded by the meter is not 0, but is read from the red needle. Every rotation of the red needle represents 10 gallons, so if your water meter reads 110 and the needle is pointing to the 8, then you have used 118 gallons of water. After you use another two gallons, the meter will read 120 on the digital scale and the red needle will be pointing to 0 on the analog scale.
*Note: If red dial turns when you have all water turned off - you have a leak.
*If red diamond shaped leak detector is turning when you have all water turned off - you have a leak.