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Old 05-05-2016, 06:51 PM
Rufus Rufus is offline
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Default Converting decimals to fractions

Hi all:
I have learned to convert decimals to fractions. I am doing it now for fun, as entertainment since I have learned how to do it. It is a skill that is needed for such as reading a micrometer caliper.

I am having problems with a problem that I came up with. Here it is:

.075 + .350. + .275 = .7

Breaking the decimals down I get....075=3/40 .350=7/20 .275=11/20 and with the .7 I came up with 7/10. Now when I add up 3/40, 7/20 and 11/20. I came up with 25/40. Breaking that down I came up with 5/8. I thought the answer would be 7/10. Obviously I came up, some how, with a gross error. Will someone show me the error of my ways?

Thanks
Tim
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Old 05-05-2016, 07:11 PM
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GWIZ GWIZ is offline
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hi all:
Now when i add up 3/40, 7/20 and 11/20. I came up with 25/40.
Thanks
tim


3/40
14/40
22/40 your error
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Old 05-05-2016, 07:13 PM
JBFab JBFab is offline
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Originally Posted by Rufus View Post
Hi all:
I have learned to convert decimals to fractions. I am doing it now for fun, as entertainment since I have learned how to do it. It is a skill that is needed for such as reading a micrometer caliper.

I am having problems with a problem that I came up with. Here it is:

.075 + .350. + .275 = .7

Breaking the decimals down I get....075=3/40 .350=7/20 .275=11/20 and with the .7 I came up with 7/10. Now when I add up 3/40, 7/20 and 11/20. I came up with 25/40. Breaking that down I came up with 5/8. I thought the answer would be 7/10. Obviously I came up, some how, with a gross error. Will someone show me the error of my ways?

Thanks
Tim
Go about it a different way, I think your conversions were in correct in the first place .075 is certainly 3/40, however let's just call it 75/1000, .350 to 350/1000 and .275 to 275/1000

So add it up:

75/1000+350/1000+275/1000=700/1000, get to the lowest common denominator by dividing each by 100 and you get 7/10
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Old 05-05-2016, 07:22 PM
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MAC702 MAC702 is offline
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...75/1000+350/1000+275/1000=700/1000, get to the lowest common denominator by dividing each by 100 and you get 7/10
This. A decimal is already a fraction, with some multiple of 10 as the denominator. Convert to the biggest one and add, then simplify.
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Old 05-05-2016, 07:25 PM
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Hi all: .275=11/20
Thanks
Tim
not

.275=11/40
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Old 05-05-2016, 07:58 PM
Rufus Rufus is offline
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not

.275=11/40
Ok. After doing a quick calculation, .275 still comes up as 11/40. Here is how I did it. .275 X 1000 = 275 On the bottom...1 X 1000 = 1000.

Breaking down 275/1000 here is what I came up with...275 / 5 = 55. 1000 / 5 = 200. Then....55 / 5 = 11. 200 / 5 = 40. That is how I came up with 11/40. Now when I take 40 into 11 I come up with .275 It does seem to come out right. Maybe I am wrong. I have been wrong on many occasions

Thanks
Tim
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Old 05-05-2016, 08:04 PM
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3/40
14/40
22/40 your error
Ok I saw the error of my ways. For example...when doing 11/20 with the lower number as 40, I took 20 into 40 which would be 2. Instead of multiplying 2 X 11 to come up with 22, I was adding, 2 + 11 coming up with 12. After I added it all up, I came up with 39/40.

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Tim
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Old 05-05-2016, 08:07 PM
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Ok. After doing a quick calculation, .275 still comes up as 11/40.
Tim
In your first post you stated 11/20 "twenty"

Not "forty"
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Old 05-05-2016, 08:08 PM
Rufus Rufus is offline
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This. A decimal is already a fraction, with some multiple of 10 as the denominator. Convert to the biggest one and add, then simplify.
I found that if there are 3 numbers to the right of the decimal, (for example, .300 then you would take .300 and multiply that by 1000 to come up with 300. If it were .30 then it would be .30 multiplied by 100 to come up with 30.
You are right. It is already a fraction with some multiplication involved.

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Tim
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Old 05-05-2016, 08:11 PM
Rufus Rufus is offline
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Originally Posted by JBFab View Post
Go about it a different way, I think your conversions were in correct in the first place .075 is certainly 3/40, however let's just call it 75/1000, .350 to 350/1000 and .275 to 275/1000

So add it up:

75/1000+350/1000+275/1000=700/1000, get to the lowest common denominator by dividing each by 100 and you get 7/10
It worked Lol I tried it and yes Ladies and Gentlemen, It worked

Thanks
Tim
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