22 7/8 is approx. 23; some people might even round that off to 25.
Need approx 25 ounces of chemical for each gallon of water. How many ounces of chemical should be mixed with 44 gallons of water?
Mult 25 (ounces/gallon) by (45 gallons). "gallon" will cancel out, leaving us with (25)(45) = 1125 ounces.
I think you'll find it easier to skip the estimation here and calculate the answer in the usual manner:
(22 7/8)(44 1/5) = 22.875(44.2) = 1011.1 ounces.