18/42 as a percentage is 42.86%. This tells you that the fraction represents a little less than half of a whole. In decimal form it is about 0.4286, which is the same value expressed in a different way.
If you simplify the fraction, 18 ÷ 6 = 3 and 42 ÷ 6 = 7, so 18/42 reduces to 3/7. Whether you write it as 3/7, 0.4286, or 42.86%, the amount stays the same—it’s the portion of something that is just under half.
Knowing the percentage makes it easy to compare with other numbers. For example, if you score 42.86% on a test, you got about 43 out of every 100 points. The same idea works for any situation where you need to see how a part relates to a whole.
