Answer: Remember how to find equivalent fractions? Here are some:
1/4, 2/8, 3/12, 4/16, 5/20, 25/100, 90/360, 1800/7200
To find all of these, there's a simple method- multiply the denominator and the numerator by the same number. As long as you make sure to use the same number for both the top AND the bottom, you'll always have an equivalent fraction. For example,
1 1800 1800
--- x -------------- = ---------
4 1800 7200
This works because, as you may have noticed, any muliplier you use is in the form of n over n, which, of course, is equivalent to one whole or 100%. Make sense?
