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Multiplying unit fractions: expression to area model

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    - [Instructor] We are
    asked to select the diagram
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    that represents 1/6 times 1/4.
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    So why don't you pause this video?
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    Have a go at it before
    we do this together.
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    Okay, before I even look at these choices,
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    I could think about what
    this might look like.
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    So if I had a square unit,
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    I'm just gonna hand draw it so
    it's a little bit shaky here.
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    So I could imagine having
    1/6 on the left side
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    and then 1/4 on top.
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    So how would I do that?
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    So I would divide it into six
    equal sections horizontally.
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    So I could do it like this.
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    So it could look something like this
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    where each of these is 1/6
    and then I'm going to multiply
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    and maybe I would put
    that maybe in that color
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    and then in the other direction
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    I would divide it into fourths.
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    So let's see, that's about half.
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    And then I will put those
    in half to get fourths.
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    So 1/6 times 1/4.
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    And so the fourth, let me
    do this in a light color
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    so it doesn't write over.
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    It would be that-
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    Well, lemme do it in the color
    that you can actually see.
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    It might be all of that right over there.
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    And then their overlap
    would be right over here.
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    So this would be 1/6 times 1/4
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    and that's actually 1/24
    of this entire square.
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    So let's see.
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    Do I see anything that looks like that?
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    Let's see.
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    This first one looks like 1/4 times 1/4.
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    That's not right.
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    This one looks like 1/6
    'cause this is 1/6 right here,
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    but it's 1/6 times 1/2
    'cause in this direction
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    we're only split into two.
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    This one over here doesn't
    look like what we did.
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    But if we turn it around and
    if we do it the other way,
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    where if we divide it into
    fourths on horizontally
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    and then into sixths vertically,
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    it looks a lot like choice C.
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    So if I divided into sixths here,
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    so if I had 1/4 times 1/6,
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    1/4 would be that entire row.
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    1/6 would be this entire column.
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    When you take their product,
    you would get that shaded area,
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    which is exactly what
    they did in choice C.
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    So this is 1/4 times 1/6,
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    and you get that shaded area.
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    So I like choice C.
Title:
Multiplying unit fractions: expression to area model
Description:

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Video Language:
English
Team:
Khan Academy
Duration:
02:06

English subtitles

Incomplete

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