Question 283191: Ok so im on adding and subtracting mixed numbers and Im so confused on how the numerator is changing with the denominator...I dont no if im making sense but here is an example...
9 3/4 + 8 5/6
the numerators changed to 9 9/12 and 8 10/12 so confused I understand how to find everything else but that!
Found 2 solutions by richwmiller, oberobic:
Answer by richwmiller(17219)   (Show Source):
You can put this solution on YOUR website! 9 3/4 + 8 5/6
9 9/12 and 8 10/12
Maybe if I ask you some questions it will clear up what is happening.
Do you see how 3/4=9/12 ?
Do you see why 5/6=10/12 ?
Can you add 9 3/4 + 8 5/6 ?
Can you add 9 9/12 and 8 10/12 ?
How would you go about adding 9 3/4 + 8 5/6 ?
What would you do first?
What would you do next?
Answer by oberobic(2304)  (Show Source):
You can put this solution on YOUR website! When you're dealing with fractions you need to get everything to the same denominator.
1/4 + 1/3 cannot be directly added using fractions.
The least common multiple of 4 and 3 is 12, so they can have the same denominator of 12.
So...
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In this case, you're trying to add 9 3/4 + 8 5/6.
The least common multiple of 4 and 6 is 12. We can figure this out by multiplying 4*6=24, but we notice that 4=2*2 and 6=2*3, so 12 is the LEAST common multiple.
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So...
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But 19/12 is more than 1, it is
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How do we know that 3/4 = 9/12?
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Well, remember the idea is the 'least common multiple'.
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To change 3/4 to 9/12 you simply look at how many times 4 goes into 12. 12/4 = 3
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So you multiply 3/4 by 3/3 (Remember, you can multiply any number by 1, in this case 1 is 3/3.)
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Similarly, how did 5/6 become 10/12?
It is the same process: 12/6 = 2
Multiply 5/6 by 1, which in this case is 2/2.
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Done
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