Question

http://prntscr.com/bdvpui
How do I find this one out?

Answer 1

@mmw

Answer 2

use the hint they gave you.... give them all the same denominator, then you can easily compare all 3 fractions and determine which is greatest

Answer 3

Hmm. Just basically just find a common denominator, for all of them, make them all the same fractions, and compare through the numerator?

Answer 4

yes, you could do that.
But before you do that, you can "analyze" it a bit.
For example, is 3/7 bigger or smaller than ½ ? any idea ?

Answer 5

Not really, but if I had to guess. 3/7 is smaller than 5/9?
But I also heard that the smaller the fraction, the bigger it is? I am just confused I suppose.

Answer 6

it's worth getting the ideas.

take a pie (we always use pies!) and divide it into 7 equal pieces
you take 3 of the pieces and your friend takes the rest. how many pieces did they get?

Answer 7

They got 4 pieces. 4 > 3. So they got "bigger" pieces than me?

Answer 8

all the pieces are the same size. you got 3 of them and they got 4
did you get more than half of the pie or less than half ?

Answer 9

Less than half/

Answer 10

which means 3/7 is less than ½
though we don't usually use decimals , 3.5/7 would be exactly half
in other words, you get 3 pieces, your friend gets 3. then you each split the last piece ,
so each of you gets 3 and ½ pieces.

Answer 11

now look at 2/5
is that less than ½ or more than ½
(we can think about the same way as above: divide a pie into 5 equal pieces. take 2 of them. is that more or less than half of the pie ?

Answer 12

That's less than half of the pie.

Answer 13

yes,

now what about 5/9 ?
less or more than ½ ?

Answer 14

More than. 4.5 would be the exactly half right?

Answer 15

yes, exactly.

usually if we had 4.5/9 we would multiply top and bottom by 2 to get 9/18
(so we have "nice" numbers, not decimals)

but you have 3 fractions , 2 are smaller than ½ and one is bigger than ½
so it's obvious which one is the biggest of the 3

Answer 16

Yeah, so 5/9 is the biggest,
So if I get this problem again, I could just compare them by using "pies"?

Answer 17

this idea won't always work, because they could make all 3 fractions less than ½,
Then we would have to do it the first way, and make them all have the same denominator.

But when I saw all 3 fractions, I solved it the way I showed you.

Answer 18

AH, thank you. You were very helpful. :3

Answer 19

Thank you for having patience with me :P