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# Equivalent fraction word problem example 2

Video transcript

Mary wants the fraction
of pink blocks in model B to be equivalent to the fraction
of pink blocks in model A. How many blocks in
model B need to be pink in order to make that happen? So let's look at model A. So how many equal
sections are there? There's 1, 2, 3, 4,
5 equal sections. There are 5 equal sections. And what fraction
of them are pink? Well, you have one
of them is pink. One of the blocks is pink. So 1/5 of the blocks over
here in model A is pink. Now, we have to think
about how to make 1/5 pink right over here. So let's think about it. So how many, first of all,
total blocks are there? There's 1, 2, 3--
let me actually do this in another color. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 13, 14, 15, 16, 17, 18, 19, 20. There are 20 total blocks here. And you see that this is
the exact same length. Model B is the exact
same length as model A. And so for every
block that you have in model A, for
every block here, you must have 4 in model B
because we went from 5 sections to 20. So we're essentially
multiplying by 4. And you even see it here. If we were to just
draw a line right down here you see, you see for
every block in model A, you have 1, 2, 3, 4
blocks in model B. So one block in
model A that is pink would be the same thing
as 4 blocks in model B. We would literally just
multiply this times 4. So 4 of the 20 will need to
be made pink, so 1, 2, 3, 4. And you see that it
exactly matches up. This is the exact same fraction
of the entire model over here. So when they say how
many blocks in model B need to be pink to
make that happen? It would be 4.