TheCatSite.com › Forums › General Forums › The Cat Lounge › More Fractions (or @#%^!!)
New Posts  All Forums:Forum Nav:

More Fractions (or @#%^!!)

post #1 of 21
Thread Starter 
As some of you know I'm trying to get a handle on basic math and some algebra before I take the only part of the placement test I have to take before I start back to school.

Fractions, namely the addition and subtraction of said fractions, have been my nemesis. Well, I'm happy and encouraged to report that I have the basics down as far as addition and subtraction of fractions. The wrench in the works is when they involve mixed numbers and borrowing from mixed numbers. I've been working at these for a while and it isn't sinking in.

Could someone be so kind as to walk me through these two examples? I know I have to find a common denominator but I keep ending up with a numerator that is larger than the denominator in my mixed number (for the addition problem). I'm not sure what I'm doing wrong.

1)2 3/4 + 3 3/8=

2)14 1/8 - 13 3/4=

Thank you!
post #2 of 21
Go until you have a common number on the bottom, 3/4 can also be 6/8 add the 2 together to get your whole number, and then you can reduce your fraction if you need to, 6/8 back to 3/4.

2 6/8 + 3 3/8 = 6 1/8

14 1/8 +13 6/8 = 27 1/8
post #3 of 21
Try these links:

http://jamit.com.au/htmlFolder/FRAC1007.html

http://www.math.com/school/subject1/.../S1U4L3GL.html


http://www.bbc.co.uk/schools/ks3bite...ions_2_3.shtml

I also encourage you to go to the library and borrow a grade 1 math book. That's what I did before I started nursing school when I had to learn fractions.

I believe the book I borrowed was called "123 Math the Easy Way"
post #4 of 21
So if you have 1/4 and 3/8 you need to get them to the same common denominator. In this case, get them both to be /8, so you can multiply.

So to get 1/4 to eighths, so need to multiply both numbers of 1/4 by two so you end up with 2/8.

From there you can add 2/8 + 3/8, which gives you 5/8.


A bit more complex - if you were trying to add 5/6 plus 3/7, the smallest common number is 42 (6 x 7) - it may not be something small and easy, and it doesn't need to be - it just has to be a number that both have in common. So to get to /42, you multiply top and bottom of 5/6 by 7 = 35/42, and then multiply 3/7 by 6 on each side to get 18/42 (because you need to multiple the bottom denominator by 6 to get to 42, so you do the same for the top).

Adding those you get 53/42. This is where it gets a little tricky - because 53 is bigger than 42, it means it's more than a whole number. A Whole number would be the same numerator and denominator - 42/42 in this case. So if you do 53-42, you are left with 11, which makes the number you're left with "1 11/42" - the 1 is 42/42, and the remainder is what was left over - 53-42.
post #5 of 21
1)2 3/4 + 3 3/8=

3/4 to eighths, multiply by 2, so you get 6/8.

So, 2 6/8 + 3 3/8 = 5 9/8. Because numerator is bigger, it's more than a whole number, so it's actually 6 1/8. Does that make sense?

2)14 1/8 - 13 3/4=

14 1/8 - 13 3/4, so we'll multiply the 3/4 by 2 again to get eighths.
14 1/8 - 13 6/8 = 1 -5/8. Obviously we can't have a negative, so we'll convert the whole number. So rather than calling it 1, we'll call that 8/8 which is the same thing. So "1 and -5/8" equals "8/8 and -5/8" (same as saying 8/8 - 5/8) = 3/8


Hope that helps... Just do lots of them - make up lots of random fractions, and add and subtract like mad, using your calculator (or an online calculator) to check your answers.

If you get stuck, feel free to PM me!
post #6 of 21
Thread Starter 
Thanks. I have a couple of books that I'm using. My sister can help but our work schedules don't allow for us to meet up and go over this stuff. I'm still a bit confused but I'm also slowly starting to figure it out. I'm going to work on a few problems. The ones where my answers don't match what they are supposed I'm going to ask about.

I did the following problem:
11 1/16 - 4 3/32. The LCD is 32 so I then ended up with this: 11 2/32 - 4 3/32; and then subtracted: 11 2/32 - 4 3/32= 7 -1/32. From there I figured that -1/32 was the same as 32/32 and did this: 32/32 - -1/32= 7 31/32. The answer in the book for this particular problem is 6 31/32. What did I do wrong?

*I'm tired. I hope this made sense and I typed it out right...lol.
post #7 of 21
Thread Starter 
I have a Barron's book called "Math The Easy Way". I just did the practice test at the end of the fractions chapter. I missed four out of fifteen questions. One was because I forgot to reduce the fraction at the end (did I mention before that I was tired?...lol).

The other three that I missed were:
A fraction whose value is the same as 3/4 is:

and

17- 15/16= I'm not sure how to do this one. The book isn't clear on a lot of things.

Then there was this one, no examples or instruction of how to do this. I did manage to a addition problem that was similar. Anyway:
7/10 x 15/16 x 20/21=

The last question, I got this right, was a word problem:
How many yards of material are needed to make five dresses if each requires 2 3/4 yards?

I did it this way: 2 3/4= 2.75 x 5= 13.75 which equaled 13 3/4, which was the answer. That was one one of the easiest questions on the test.
post #8 of 21
Quote:
Originally Posted by Essayons89 View Post
I did the following problem:
11 1/16 - 4 3/32. The LCD is 32 so I then ended up with this: 11 2/32 - 4 3/32; and then subtracted: 11 2/32 - 4 3/32= 7 -1/32. From there I figured that -1/32 was the same as 32/32 and did this: 32/32 - -1/32= 7 31/32. The answer in the book for this particular problem is 6 31/32. What did I do wrong?
11 1/16 = 11 2/32
- 4 3/32 = - 4 3/32

Note that the fracture of the second number is a larger number than the fraction of the first number - can't do it, so you have to borrow from the first whole number. Remember that 1 = 32/32, so you aren't really changing the equation, you are borrowing. You are going to add the 32/32 to the 2/32, giving you 34/32 (Yes, that is not considered a correct fraction, but it is only temporary). Now you have:

10 34/32
- 4 3/32

You always work from the right side toward the left, so start with the fraction - in case you need to borrow again. 34/32 - 3/32 = 31/32, which can't be reduced. 10 - 4 = 6 The answer is 6 31/32
post #9 of 21
Fraction whose value is the same as 3/4: 6/8, 12/16, 24/32


17 is the same as 17 0/16
- 15/16 is the same as - 15/16

So borrow a 1 from the 17, which would be 16/16, so you have:

16 16/16
- 15/16
16 1/16


Mutiplying fractions:
1. Mutiply the numerators (top number) together
2 Multiply the denominators (bottom number) together
3. Simply or reduce the fraction, if possible

7/10 x 15/16 x 20/21
Mutiply the numerators 7 x 15 x 20, which is 2100
Mutiply the denominator 10 x 16 x 21, which is 3360
Reduce or simply the fraction. Get rid of the zero at the end of both numbers. That leaves 210/336 Both numbers are divisible by 3, which is 3/3, so you divide the 210 by 3 (getting 70) and the 336 by 3 (getting
112). So you have 70/112, which is an even number, so it is divisible by 2. Divide 70 by 2 (35) and divide 112 by 2 (56) so you have 35/56, which is the answer.
post #10 of 21
Looking at those are making my brain hurt
post #11 of 21
Quote:
Originally Posted by Rosiemac View Post
Looking at those are making my brain hurt
and mine!! I only had my maths GCSE exam about 3 weeks ago on all of that stuff and I've forgotten it already!

FRACTIONS = POOP!
post #12 of 21
My wife the math teacher might be able to help you. Of course, unless you have free long distance, it might be an expensive call!
post #13 of 21
I hope calculus doesn't involve fractions
post #14 of 21
Quote:
Originally Posted by katiemae1277 View Post
I hope calculus doesn't involve fractions
Aw, such lovely foolish hopes!
post #15 of 21
Thread Starter 
Thanks for the explanations, Mom of 4. I'm going to work on some more tonight until this sinks in. Thanks to all of help I've received the last day or so, I've made a lot of progress.

I understand why I struggled with math in grade school and high school. I didn't have a firm understanding of some of the basics. I would get frustrated and just barely skate by with what I could do and make a lame attempt at what I didn't. As a result I had the typical "I hate math/can't do math" attitude. That has been changing since I started trying to re-learn the basics a couple months ago in preperation for my test. I enjoy doing them, especially when getting them right. I do get frustrated from time to time but that frustration is what is driving me to learn how the problems are solved.
post #16 of 21
Quote:
Originally Posted by Rosiemac View Post
Looking at those are making my brain hurt
You're not alone..

I'm horrible at math.. anything beyond basic math anyways.
With that said, I wish you luck..
post #17 of 21
Thread Starter 
I applied at the FAFSA website to see if I can get some sort of financial aid. Hopefully, I'll be able to get enough to cover a class or two every quarter.
post #18 of 21
If you don't do well on the placement tests, they may require you to take a remedial math class to get you up to speed. I think you will like it as they will be able to help you understand the processes that confuse you.

Math is very logical, which is what appeals to me.
post #19 of 21
Thread Starter 
Quote:
Originally Posted by Mom of 4 View Post
If you don't do well on the placement tests, they may require you to take a remedial math class to get you up to speed. I think you will like it as they will be able to help you understand the processes that confuse you.

Math is very logical, which is what appeals to me.
To be honest, I'm fine with that and it will benefit me in the long run. I can take a basic math class before I take my placement test but it would have to be as a non-degree seeking student. I can change my status back to a degree seeking student after taking the test.

I'm actually starting to like math.
post #20 of 21
Quote:
Originally Posted by Forensic View Post
Aw, such lovely foolish hopes!
a girl can dream
Quote:
Originally Posted by Essayons89 View Post

I'm actually starting to like math.
I'm starting to worry about you, Bryan
post #21 of 21
Thread Starter 
Quote:
Originally Posted by katiemae1277 View Post
I'm starting to worry about you, Bryan
I'm a strange bird.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: The Cat Lounge
TheCatSite.com › Forums › General Forums › The Cat Lounge › More Fractions (or @#%^!!)