Placeholder Image

字幕列表 影片播放

  • Brandon ate 5 slices of apple-- of pie.

  • I'm just assuming it's apple pie.

  • They didn't tell me that.

  • Gabriela ate 3 slices.

  • If there were originally 9 slices,

  • what fraction of the pie was eaten?

  • So let me see if I can draw this thing out.

  • So let me draw the pie.

  • I will draw the pie in a yellowish color.

  • So let me try my best.

  • So let's see how good I am at drawing a pie.

  • So I'll just draw it from the top view as a circle.

  • And there're 9 slices.

  • I think it's a reasonable assumption

  • to say that they're 9 equal slices.

  • So we have 9 equal slices of pie.

  • And I'll just make sure they're initially 9 equal slices.

  • What fraction of the pie was eaten?

  • So let's first divide this into 9 sections.

  • So one way I could do that, I could divide it into 3 sections

  • first, so it looks like a peace symbol.

  • It actually looks more like the Mercedes emblem.

  • So I'll draw it into 3 sections first.

  • Then I'll do each of those into 3 sections, and I'll have 9.

  • So let's see, I'll draw like that and like that.

  • Keep in mind, I'm trying to make these as equal as possible.

  • So bear with me if they don't look 100% equal,

  • but I'm trying.

  • I am trying my best.

  • So 9 equal slices-- so that looks pretty respectable.

  • So here's our pie that initially had 9 equal slices.

  • Now, they tell us that Brandon ate 5 slices of pie.

  • So Brandon eats-- he seems like a hungry young man--

  • so he eats 1, 2, 3, 4, 5.

  • You could say that he ate 5/9 of the pie.

  • But that's not it.

  • That's not what they're asking.

  • It's saying total, not just how much did Brandon eat,

  • but how much was eaten total between Brandon and Gabriela.

  • And they tell us Gabriela ate 3 slices.

  • So she ate 1-- sounds like they didn't really

  • eat dinner-- 1, 2, 3.

  • So now let's answer their question.

  • What fraction of the pie was eaten?

  • Well, we know that there was a total of 9 equal slices of pie.

  • What fraction was eaten?

  • Well, as we see, 1, 2, 3, 4, 5, 6, 7, 8.

  • 8/9 of the pie was eaten.

  • So let's actually type that in.

  • And then we will do it right over here.

  • We'd say 8, and we use that little slash symbol

  • on your computer like this.

  • 8 over 9 or 8 divided by 9 or 8/9 of the pie was eaten.

  • Let's do a couple more of these.

  • Ishaan ate 2 slices of pizza.

  • Omar ate 3 slices.

  • If there were originally 8 slices,

  • what fraction of the pie is remaining?

  • So this is interesting.

  • Actually, let me copy and paste this

  • so that I can do it on my little notepad right over here.

  • So let's do it right over-- trying to find some space.

  • There you go.

  • Let me put that in here.

  • So the same thing, we have-- well,

  • this is a pizza now, not a pie.

  • And so pizza I will draw in brown.

  • It has 8, and we can assume it's initially 8 equal slices.

  • So it's actually a little bit easier to draw 8 equal slices,

  • since 8 is an even number.

  • So let's see.

  • That is my best attempt at drawing a circle.

  • And let's see, first I can divide the pizza into 2 slices,

  • then I can divide it into 4 slices.

  • And I'm going to try to make them look as equal as possible.

  • And now I'm going to-- with two more cuts,

  • I should be able to get 8 so-- and one more just like this.

  • So there you have it, a pizza that has 8 equal slices.

  • Now, they tell us Ishaan ate 2 slices of pizza.

  • So he eats 1, 2 slices of pizza.

  • Omar ate 3 slices.

  • Omar ate 3.

  • So he eats 1, 2, 1, 2, 3 slices of pizza.

  • Now, you might immediately say, oh, OK,

  • the answer to this must be 1, 2, 3, 4, 5.

  • It must be that they ate 5 slices of pizza

  • over a total of 8 slices of pizza.

  • So they ate 5/8 of the pizza.

  • You would be right in saying that they ate 5/8 of the pizza,

  • because they ate 1, 2, 3, 4, 5 out of a total of 8 pieces.

  • But that's not what this question is asking.

  • They are asking, what fraction of the pizza is remaining?

  • So what's left over after Ishaan and Omar

  • had their go at the pizza?

  • Well, what's remaining is 1, 2, 3 slices.

  • So what's remaining is 3 out of the original 8 equal parts

  • or 3/8 of the pizza is remaining.

  • So let's input that.

  • So we could go right here.

  • And we would say 3 over 8, 3/8, is remaining.

  • So let's check our answer, and we got it right.

Brandon ate 5 slices of apple-- of pie.

字幕與單字

影片操作 你可以在這邊進行「影片」的調整,以及「字幕」的顯示

A2 初級

計算出還剩多少比薩餅|分數|四年級|可汗學院 (Figuring out how much pizza is left | Fractions | 4th grade | Khan Academy)

  • 66 5
    VoiceTube 發佈於 2021 年 01 月 14 日
影片單字