Math Question

essayons89

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I'm cornfused.


I'm trying to figure out how to add fractions that have different denominators and can't quite get it. Can someone please explain how to do this in easy to follow steps?

I'll give a couple of examples:

2/10 + 3/5=

3/4 + 4/7=

I know I have to find a common denominator but my answers don't always end up jiving with the answers for the exercises. I'm getting frustrated.


Thanks.
 

going nova

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Originally Posted by Essayons89

I'll give a couple of examples:

2/10 + 3/5=

3/4 + 4/7=
Example 1:

2/10 + 2/5 = ?

You need to get the same denominator on the bottom. For the first term the denominator is 10. For the second term the denominator is 5. You then think... 2 x 5 = 10. So, you multiply both the top and bottom parts of 2/5 by 2 to get 4/10. (You are able to do this because 2/2 = 1.)

When you add 2/10 + 4/10 = 6/10

You can reduce this fraction because you can divide 6 by two, and you can divide 10 by two. So this gives you 3 on the top and 5 on the bottom.

Your answer is 3/5.

If that was confusing, maybe I can think of a different way to explain the second one?
 

valanhb

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I could be wrong, since math is really not my forte, but I think I remember fractions...

You're right, the key is common denominators. In the case of the first example, it's easier because you can reduct 2/10 to 1/5 (divide both sides by 2) and then add to get 4/5.

The second is trickier because you can't divide either. So the key is to find the multiplier that will get the common denominator. In this case, I think you multiply to get the denominator of 28. So 3/4 (multiply both by 7) = 21/28; 3/7 (multiply both by 4) = 16/28. 21/28 + 12/28 = 37/28 or 1 9/28.

I think. I could be wrong. I usually get the wrong answers to the Math questions on Are You Smarter Than A 5th Grader.
 

going nova

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Originally Posted by Essayons89

3/4 + 4/7=
For this example, you can't multiply 4 by any number to get seven, so what you do is multiply them by each other!

It will look like this:

(3 * 7) +
(4 * 7)

(4 * 4) =
(7 * 4)

21+16=37
28 28 28

You see that 28 goes into 37 a total of once. And you have 9 left over. (37= 28 + 9) So if you need to write this as a mixed number, you have: 1 and 9/28
 
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essayons89

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That helps out a lot! Thank you! I'm trying re-learn before taking my placement test (math is the only portion I need to take) out of a book and sometimes I it helps more to have a person explain it. I have a lot of practicing to do yet.
 
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essayons89

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Originally Posted by luvmycat1

I suck at Math
Good luck to you.
Thanks, me too! I want to learn it though. The better I do, maybe the less classes I'll have to take. This is the first time I touched fractions in almost 20 years. Makes me feel old.
 

h~chan

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Originally Posted by luvmycat1

I suck at Math
Good luck to you.
I'm so glad I'm not alone in the world.. I'm horrible at math!


(Good luck
)
 

valanhb

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Bryan, I know it wasn't your intention but this really made my night (unless the Avs win!) because I was actually able to DO a math question!
Usually I suck at math too, but I was always pretty good at fractions.
 
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essayons89

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You're welcome.
Math is fun when you get them right. I can talk history until I'm blue in the face but my brain cramps up when it comes to math. If you think this was fun just wait until I need help with algebra.
 

abbycats

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I always break the fractions down to decimals and then go from there in my math. Getting them back to a fraction after that well... I cheat and use a chart. I had to do this at work when I was in a fabrication dept.

Math is not my thing...
 

pookie-poo

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It's kind of nice to know that I'm not the only 'math challanged' individual here! My version of Hell would involve fractions, algebra, and differential equations.
 

katiemae1277

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Originally Posted by Essayons89

Thanks, me too! I want to learn it though. The better I do, maybe the less classes I'll have to take. This is the first time I touched fractions in almost 20 years. Makes me feel old.
shows how much you acutally use them, eh?


I have to take Calculus with Business Applications and I was going to take a refresher Algebra course, but I know algebra, so I'm diving in
I think there are sharks in the water, though
I might be getting a tutor for this one
 

white cat lover

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Originally Posted by katiemae1277

shows how much you acutally use them, eh?


I have to take Calculus with Business Applications and I was going to take a refresher Algebra course, but I know algebra, so I'm diving in
I think there are sharks in the water, though
I might be getting a tutor for this one
You're brave! I took easy math, the refresher course...then found out that it fulfilled my needed math credit for my degree, so I quit there.


Math + me =
 

twstychik

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Originally Posted by Essayons89

Thanks, me too! I want to learn it though. The better I do, maybe the less classes I'll have to take. This is the first time I touched fractions in almost 20 years. Makes me feel old.
I just have one suggestion... do NOT guess! If you don't know an answer leave it blank. If you guess and you get it right you could place higher than you are able to handle.
 

katiemae1277

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Originally Posted by white cat lover

You're brave! I took easy math, the refresher course...then found out that it fulfilled my needed math credit for my degree, so I quit there.


Math + me =
brave or stupid
Calculus is the required math course so I'm stuck
the only way that I'm able to just take it without any other math is that I took pre-calc many moons ago during my first round of college
 

butzie

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Originally Posted by katiemae1277

brave or stupid
Calculus is the required math course so I'm stuck
the only way that I'm able to just take it without any other math is that I took pre-calc many moons ago during my first round of college
I liked Calc and I aced it, so if you have any questions...
 
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essayons89

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Originally Posted by twstychik

I just have one suggestion... do NOT guess! If you don't know an answer leave it blank. If you guess and you get it right you could place higher than you are able to handle.
Good advice, I plan on following it. To be honest I don't know what level of math I have to end up at being a history major.
 
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