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#1 2005-02-09 19:35:59
- katey
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maths
can you tell me good web pages for maths plus can you help me with fractions the times it is really hard and i always get them wrong
#2 2005-02-09 21:11:01
- MathsIsFun
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- Registered: 2005-01-21
- Posts: 7,713
Re: maths
Well, we like this website! (Of course)
We have some pages here that tell you how to deal with fractions. Adding, subtracting multiplying and dividing.
For example, to multiply 1/4 by 2/3 you just multiply the top bits by the bottom bits:
1/4 x 2/3 = 1x2 / 4x3 = 2/12.
2/12 can be simplified to 1/6
You can read more about this at Multiply Fractions
"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman
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#3 2005-02-10 05:48:37
- Barker
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- Registered: 2005-02-10
- Posts: 2
Re: maths
My daughter's homework is can you write down the properties of a cube? It is a 3D cube. Is the answer 12 sides.
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#4 2005-02-10 08:38:56
- MathsIsFun
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- Registered: 2005-01-21
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Re: maths
A 3D cube is just a simple box. So it has a top and a bottom, a front and back and a left and right side. In othe words just 6 sides. But if you count the edges, there are 12.
You can find out more here: Platonic Solids
"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman
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#5 2005-02-12 05:12:43
- msg21252
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- Registered: 2005-02-12
- Posts: 1
Re: maths
need formula on how to figure percentages from a whole number example: total amount for item is $3500.00, Joe's 20% is included in this number. How much does Joe get?
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#6 2005-02-12 10:47:43
- MathsIsFun
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- Registered: 2005-01-21
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Re: maths
Percentages just mean "per 100" so 20% means "20 per 100"
Your particular problem MAY be as simple as calculating 20% of 3500, (which is 20/100 x 3500 = 20 x 3500/100 = 20 x 35 = $700)
But perhaps they mean "there was a price, Joe got 20% of that, and the total is $3500"
In that case it is a little harder.
You would figure it this way: you know that $3500 = "The Unknown Price" + 20% of "The Unknown Price" = 120% of the unknow price.
And 120% is 120/100, which is really just 1.2
So, "The Unknown Price" x 1.2 = 3500
Dividing both sides by 1.2 gets:
"The Unknown Price" x 1.2 / 1.2 = 3500 / 1.2
"The Unknown Price" = 3500 / 1.2
"The Unknown Price" = 2916.67
And Joes 20% would be 20/100 * 2916.67 = 583.33
(Confirming this: 2916.67 + 583.33 = 3500)
Was that a help?
"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman
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