If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Cutting shapes into equal parts

Lindsay figures out if 4 pieces of pie are each equal to 1/4 of the pie. Created by Lindsay Spears.

Want to join the conversation?

  • blobby green style avatar for user pearsoa2
    before humans discovered gravity were we just floating around...?
    (17 votes)
    Default Khan Academy avatar avatar for user
  • winston baby style avatar for user daberechi egeonu
    What is the line between fractions called?

    It's called the vinculum, but it can also be called the fraction bar or division bar.
    (4 votes)
    Default Khan Academy avatar avatar for user
  • aqualine ultimate style avatar for user Agiboygoat
    From to why didn't she use a pizza as the representation.
    (5 votes)
    Default Khan Academy avatar avatar for user
  • primosaur sapling style avatar for user leo.lin.2022
    is 1/4 = to 1/8?
    (0 votes)
    Default Khan Academy avatar avatar for user
    • male robot hal style avatar for user authentic8
      1/8 is actually half of 1/4. Interesting!

      That might sound strange because 8 is 2 times 4. But remember we are talking about fractions. If you imagine a pie that has been divided into 4 equal pieces and a pie of the same size that is divided into 8 equal pieces, each piece of the second pie is going to be half the size of the pieces in the first pie.

      Think of it another way with only one pie. If you cut the pie into quarters (1/4) so you have 4 equal pieces of pie, and then cut each of those quarter pieces in half, you would have 8 pieces of the pie - each slice is now one eighth (1/8) of the pie. As you cut the quarter (1/4) in half, the eighth (1/8) is half the size of the quarter.

      Did that help?
      (2 votes)
  • male robot donald style avatar for user KhilynT
    i don't got a question
    (4 votes)
    Default Khan Academy avatar avatar for user
  • blobby green style avatar for user ahdadyas000
    The bottom row is called the denomerater.
    (2 votes)
    Default Khan Academy avatar avatar for user
  • aqualine ultimate style avatar for user Divyamaukthika Challa
    Does a fraction have to be an equal? Why can it not be improper or not equal?
    (2 votes)
    Default Khan Academy avatar avatar for user
    • stelly blue style avatar for user Kim Seidel
      By definition, the denominator (the bottom number) in a fraction tells you how many equal sized part will create 1 whole unit. For example: 3/4, the 4 tells you that it take 4 equally sized parts to make a whole unit. The 3 in the numerator tells you that you have 3 parts.

      If a shape is cut into unequal portions, then you need to know the size of each portion to determine their fraction of the whole. Then, to find one fraction, you would have to add the fractions together to find the total fraction. You can only add fractions of equal size (denominators match), so there is a process you have to go thru to convert the fractions to a common denominator.

      Hope this helps.
      (1 vote)
  • female robot ada style avatar for user ᕼᗩYᒪEI
    Doese any one know how to multiply fractions?
    (1 vote)
    Default Khan Academy avatar avatar for user
  • stelly green style avatar for user 44968
    why do we say 2/8 when there is 1 pie?:'
    (2 votes)
    Default Khan Academy avatar avatar for user
  • aqualine sapling style avatar for user kaleb adorno
    thu is suck
    (2 votes)
    Default Khan Academy avatar avatar for user

Video transcript

- [Voiceover] Is each piece equal to 1/4 of the area of the pie? So we have a pie, and it has one, two, three, four pieces. So it does have four pieces. So is one of those pieces equal to 1/4 of the pie? Well let's talk about what we mean when we have a fraction like 1/4. The one in the fraction, the numerator, represents a number of pieces. So here, one piece. One piece of pie. And then the four, when we're talking about fractions is always talking about the number of equal size. Equal size pieces. So in this case four equal size pieces. So the question is, is each piece one of four equal size pieces? Let's look at the pie. I think it's pretty clear that these pieces on the end are not equal, they are smaller than the two pieces in the middle. If you love cherry pie, you are not happy about getting this end piece. Because it is smaller. It is not an equal size piece. So yes, each piece is one out of four pieces. But it is not one of four equal size pieces. Therefore it is not 1/4. So our answer is no. No, no, no. Each piece is not 1/4 or an equal share of the pie.