8 = Pints in a Gallon
8 equals fingers on the human hand (plus 2 thumbs)
This is a ditloid. The answer is 9 = gallons in a firkin.
Fifth-Generation Language
9 stripes in the Greek flag
a perfect game in bowling
2 lenses in a standard pair of glasses
One Man's Loss is Another Man's Gain
The ditloid "100 equals Z in a G" stands for "100 Zulu (or Z) in a Grade." It refers to the fact that there are 100 Zulu (or Z) in a Grade, which commonly refers to temperature scales, specifically in reference to the Fahrenheit scale where 100 degrees is a notable temperature.
2=O in G and Y(Two O's in Google and Yahoo)
3 hands of a clock
Gold Medals Won by Team GB at the Beijing Olympics
2 Lenses in a Standard Pair of Glasses2 lenses in a standard pair of glasses