When calculating ratios, think of it as finding out how much of a total is in one place and how much of the total is in another place. Discover how ratios differ from fractions with help from a science teacher in this free video on calculating ratios.
Hi, I'm Steve Jones, and I'm going to explain how to calculate ratios. Now, the ratio is like a proportion. It is not a fraction, though it is similar to a fraction. Here, we have a set of boxes, and in these boxes, whatever there are, they're saying, let's say there is ten objects in each box, so we know that we have in these boxes all together, sixty objects, but we know we've got six boxes, ten in each, sixty objects, and we know that the number of red, is actually, the number in the red boxes is twenty, because there are two boxes full of those, and therefore the number not colored, that's in the not colored boxes, is forty, and what we say is, if there are twenty of these, and forty of these, the ratio is found by canceling these down. Well, obviously, we could also use the number of boxes, but we'll cancel these down by ten. That's two to four, right? which is two boxes to four boxes. That is the ratio of boxes, but ultimately, the ratio is the lowest number. One here, to two there, so for every one here, we have two here, so the ratio of colored to non-colored, is one to two, written 1:2, so a ratio is simply telling you how much of the total is in one place, and how much is in the other. This is not a fraction. A fraction tells you how much is in one place, compared with everything, but this is how much in one place, compared to another, so that is briefly how to calculate ratios.