Math Is Fun Forum

rune2402

Banned

Registered: 2007-10-23

Posts: 32

Convert to base 10

Please, convert 324 to base 10.

I am assuming this problem involves the following:

324=

3 multiplied by 10 to the 2nd power + 2 multiplied by 10 to the first power + 4 multiplied by 10 to the zero power=324

Sorry , but I cannot get the exponents in here from word. I hope you understand what i mean. Any help appreciated.

luca-deltodesco

Member

Registered: 2006-05-05

Posts: 1,470

Re: Convert to base 10

what base is the number in at the moment? Otherwise it is not possible since you would get a different answer for different base.

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mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Convert to base 10

You've kind of got the right idea, but you need to use the base that you're currently in, rather than 10.

Say that your 324 is in base 5.
Then to convert it to base 10 you'd do 3*5² + 2*5 + 4 = 75+10+4 = 89.

In general, if your number is base x (where x has to be at least 5), then its base 10 value would be 3x² + 2x + 4.

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rune2402

Banned

Registered: 2007-10-23

Posts: 32

Re: Convert to base 10

Hmm! My instructor has not specified a base for the number 324 which she wants us to convert to base 10 for extra credit.

luca-deltodesco

Member

Registered: 2006-05-05

Posts: 1,470

Re: Convert to base 10

well look at the work youve been doing, what base have the numbers been in? if she has not declared it here, its likely to be whatever base you've been using

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The Beginning Of All Things To End.
The End Of All Things To Come.

rune2402

Banned

Registered: 2007-10-23

Posts: 32

Re: Convert to base 10

I think she wants the answer in such a way that the exponents correspond to the digits place in the original number. Hundreds, tens, ones.

Thanks.

rune2402

Banned

Registered: 2007-10-23

Posts: 32

Re: Convert to base 10

I believe it's base 10.

Devantè

Real Member

Registered: 2006-07-14

Posts: 6,400

Re: Convert to base 10

In case of emergency, best to just to do all the bases from 1-20 and convert all of them. That's what I would do if I wasn't sure.

If your coursework or homework or whatever is to do that then ask her what is required.

rune2402

Banned

Registered: 2007-10-23

Posts: 32

Re: Convert to base 10

I'll be back. Thaks. Nice guys here. Appreciated.

rune2402

Banned

Registered: 2007-10-23

Posts: 32

Re: Convert to base 10

Oh I just discovered it's base 5. Covert 324 from base 5 to base 10. No idea how to do this. Any help appreciated.

TheDude

Member

Registered: 2007-10-23

Posts: 361

Re: Convert to base 10

Use the method mathysperson said:

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Wrap it in bacon

rune2402

Banned

Registered: 2007-10-23

Posts: 32

Re: Convert to base 10

Ok I think I got it:

http://img3.freeimagehosting.net/image.php?e7b2b66809.jpg

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Convert to base 10

The blue bit isn't right.

For one thing, it's sort of the way to convert from base 10 to base 5 (so you're doing the opposite of what you want to) and you've also put a digit greater than 4 in your answer.

That 12 in the "25"s column should actually be 22, meaning two 125s and two 25s.

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rune2402

Banned

Registered: 2007-10-23

Posts: 32

Re: Convert to base 10

Thanks. Ill look into that, but did I get the right answer?

Wait 12 x 25 =300

Your way 22 x 25=550 ???

If my numbers are wrong, how come i got the right answer, and so straightforwardly?

I used this link to get the answer, and then i tried working it out to match the answer:

http://www.triumphpc.com/base/index.shtml

Hehe! My professor says it's right. I do  not say you are wrong, but I need more elaboration. I mean she could be wrong.

Last edited by rune2402 (2007-11-07 09:58:18)

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Convert to base 10

You got the right answer, but only the part of your picture written in red was needed.
I think I misinterpreted what you were trying to do in the other bits.

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Why did the vector cross the road?
It wanted to be normal.

rune2402

Banned

Registered: 2007-10-23

Posts: 32

Re: Convert to base 10

Well yes that because the red is the answer, the other stuff was my re[presentation to the professor as to how I reasoned. Thanks again for the help. It is really appreciated.