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#1 2006-07-06 18:43:15

babyangel1972
Member
Registered: 2005-12-12
Posts: 18

Freshen up my fraction skills

I have always hated fractions....Can you give me some pointers (how do you solve the problems below) 

1.  Reduce the fractions to the lowest terms that make whole or mixed numbers.

14/4=

38/8=

14/6= 

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2.  Where do I begin with these???????
   
              6  3/5  x  1  2/8  =

              2 2/5   +  6  3/4  =

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#2 2006-07-06 20:29:51

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,711

Re: Freshen up my fraction skills

You can read the really nice pages starting here: Fractions

1.
14/4 = 7/2 = 3 1/2
38/8 = 19/4 = 4 3/4

2.
Start off by turning them into "improper" fractions (ie not mixed fractions) coz they are easier to multiply:

6  3/5  x  1  2/8  = 33/5  x  10/8  (Note: 10/8 can be simplified to 5/4 if you want)

Then multiply top and bottom parts:

33/5  x  10/8 = (33x10) / (5x8) = 330/40

Then simplify:

330/40 = 33/4 = 8 1/4

The exercises seem to be based around improper/mixed fractions. So you might want to read Improper Fractions


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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#3 2006-07-07 06:28:34

John E. Franklin
Member
Registered: 2005-08-29
Posts: 3,588

Re: Freshen up my fraction skills

Nice work MIF,

Now let's say you have to multiply them instead of add!!

     2 2/5   x  6  3/4  =  ???
Do these four things and add them up.
1.   2 x 6 = 12

2.   2/5  x  3/4 = 6/20

3.   2/5 x 6  =  12/5

4.   3/4 x 2 = 1 1/2  I recommend memorizing 3/4 times 2 is 1 and a half.
So then add up 1 to 4.

12 + 6/20 + 12/5 + 1 1/2 = ????

Denominators are none, 20, 5, and 2, so let's use 10 in denominator since 6 is even: 3/10 is 6/20.

120/10  + 3/10 + 24/10 + 10/10 + 5/10 = ????

If you don't understand the last line, say "Thunder 113", and I will try to explain!!

123 + 24 + 15
147 + 15
162/10 = 16.2
So I get 16.2 if we multiply instead of add.


igloo myrtilles fourmis

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#4 2006-07-07 08:28:03

mikau
Member
Registered: 2005-08-22
Posts: 1,504

Re: Freshen up my fraction skills

darn it! Thanks a lot Mathsisfun... >:-( Now I'm craving pizza!

Fractions may seem complicated at first but there actually isn't a whole lot to them. Converting to equal denominators is as hard as it gets, multiplying and dividing is a piece of...pizza!

One rule that cannot be stressed enough is the numerator and denominator can ALWAYS be multiplied or divided by the same number (except zero) without changing the value of the fraction. This ONE rule is all you need to add subtract or reduce fractions and everyone always seems to forget it.

Another thing, you often get word problems like "find three fifths of seven twelths" a lot of people get 
confused with this sort of wording. In math the word "of" usually means "times" (except when dealing with functions "sine of x, square root of x, natural log of x, f of x")
So just replace the word "of" with "times" and you get "find three fiths times seven twelths"

3/5 * 7/12 = 21/60.

This also applies to percents. When we say 50% OF 200 we really mean 50% TIMES 200. "%" means "one hundredths" or "over one hundred" or " divided by 100" . So 50% of 200 means:

50/100 * 200.

I honestly think if you know how to add subtract, multiply and divide, one could learn all there is to know about fractions, decimals and percents in one week (including the fact that they are all the same thing). Though it would take long term practice to get sharp, there really isn't a whole lot to remember.


A logarithm is just a misspelled algorithm.

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#5 2006-07-07 08:36:53

babyangel1972
Member
Registered: 2005-12-12
Posts: 18

Re: Freshen up my fraction skills

Thank you everyone!!!!

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