Fractions in context

In this video, we're going to think about how fractions can be used to represent things in the real world. So, here we're told that on the sharks dive team, there are three divers. In third grade, there are eight total divers on the team. What fraction of Shark's dive team is in third grade?

So pause this video and see if you can figure that out.

All right, so first of all, they tell us there are eight total divers on the team. So maybe I'll represent each diver with a little circle like this. I'll try to make it look kind of like a diver. So that's not quite a circle, but you get the idea. It looks like something kind of diving down.

So, one, two, three, four, five, six, seven, and eight. Now, if we were to talk about just one diver here, just like that, that would be one out of the eight, or we would often call that one eighth. So, eight with the "h" at the end, that is one eighth right over there.

Or I could represent it like this. I could say this is one eighth. This is one of the eight members of our dive team. Now, they tell us that there are three divers in third grade. What fraction of Shark's dive team is in third grade? So, that is, let's say it's these three. So there's three out of the eight.

So if you wanted to represent that as a fraction, you could represent it as three eighths like this, or you could represent it as, if you wanted to write it out as a word, three instead of having it three over eight, you could write three eighths like that.

If you're doing this on Khan Academy, there would be some choices out there where you'd pick one of the correct choices. But you could represent the fraction of Shark's dive team that is in third grade either as three over eight, three eighths, or three and then spell out the word "eighths."

Let's do another example. Here we are told Yuma divided his clay into four equal parts. He made clay animals out of three of the parts. What fraction of the clay did Yuma use to make clay animals?

Once again, pause this video and think about it.

All right, so let's just imagine that this is his clay initially, and he divides it into four equal parts. So let's say he divides it like this, and let's say that I have divided it into four equal parts. These all have the exact same amount of clay in them, hand-drawn, so it's not going to be perfect the way I drew it, but let's assume they all have the exact same amount of clay.

Now, it says that he made clay animals out of three of the parts. So maybe this part right over here he was able to make a clay animal out of. This part right over here he made a clay animal out of. And then that part right over there, he made a clay animal out of.

So what fraction of the clay did he use to make clay animals? So what would you call each of the equal parts? So if I were to just focus on that right over there, you would call that a fourth. A fourth. You could also represent it as one fourth like that, or you could represent it as one-fourth. That's if you were to circle one of these equal parts, that one or that one or that one or that one.

Now, if you're talking about all of his clay, what are you talking about? Well, you could view it as four fourths, four fourths, or four over four. This would also be read as four-fourths. That would be referring to all one, two, three, four of his clay.

Now, if you wanted to say what fraction of the clay did Yuma use to make clay animals, we can see that three of the fourths were used to make clay animals. So to answer that question, we would say three of the fourths. So, three fourths were used to make clay animals. You can also express that as a fraction. You could also write that as three fourths like this.

You would read these the same: three-fourths or three-fourths. Three out of the four equal sections of clay were used to make the clay animals.