Quarts in a Gallon

Date: 03/20/2001 at 21:50:10
From: Christine
Subject: Quarts, gallons

I am having trouble finding out how many quarts are in a gallon, and 
so on. Is there a math problem I can learn by heart without having to 
memorize the whole chart, or something that would be a lot easier?

Date: 03/21/2001 at 14:28:41
From: Doctor Peterson
Subject: Re: Quarts, gallons

Hi, Christine.

When you're working with units, you have to remember at least one fact 
about each unit; but you can usually limit it to that. In the case of 
quarts, and so on, I just remember a series of 2's:

    1 gallon      = 2 half-gallons
                      (this is the trick part, but milk cartons 
                      make this seem like a natural unit to use)
    1 half-gallon = 2 quarts
    1 quart       = 2 pints
    1 pint        = 2 cups

If you need to go further, the last step is a bit bigger, but still a 
power of 2:

    1 cup = 8 fluid ounces.

It's also of interest that a pint of water weighs something close to a 
pound; so "a pint's a pound," and since there are 16 fluid ounces in a 
pint and 16 ounces in a pound, a fluid ounce of water weighs about an 
ounce. Things almost start to make sense!

Let me know if that's not the sort of thing you need.

- Doctor Peterson, The Math Forum
  http://mathforum.org/dr.math/