Math Question: What does it mean, if a number has a "line" on top of it?

ndee

Lifer
Jul 18, 2000
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Like 7.08 but on the 8, there is a "-" on top of it. What does that mean?
 

ndee

Lifer
Jul 18, 2000
12,680
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Originally posted by: Stojakapimp
that the 8 goes on forever, like 7.08888888888

Ah ok. Thanks! The question is, I have to write 7.08888888888... as a breach, how would I do that? 0.8... == 8/9, right?
 

ndee

Lifer
Jul 18, 2000
12,680
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Originally posted by: cirthix
high school freshman? with that many posts WOW

nope, I just have to refresh my math stuff cuz I really suck at math. That's why I need to work everything up.
 

TheLonelyPhoenix

Diamond Member
Feb 15, 2004
5,594
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Originally posted by: ndee
Originally posted by: Stojakapimp
that the 8 goes on forever, like 7.08888888888

Ah ok. Thanks! The question is, I have to write 7.08888888888... as a breach, how would I do that? 0.8... == 8/9, right?

wtf is a breach?

If that means "fraction", then yes, you would write it as 7 8/9 or 71/9.
 

So

Lifer
Jul 2, 2001
25,923
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Originally posted by: ndee
Originally posted by: cirthix
high school freshman? with that many posts WOW

nope, I just have to refresh my math stuff cuz I really suck at math. That's why I need to work everything up.

Wow. Seriously, that is like 7th grade math, if that high level. You really do suck at math. :D

Originally posted by: ndee
Originally posted by: Stojakapimp
that the 8 goes on forever, like 7.08888888888

Ah ok. Thanks! The question is, I have to write 7.08888888888... as a breach, how would I do that? 0.8... == 8/9, right?


'a breach'

you mean a fraction? :confused:
 

ndee

Lifer
Jul 18, 2000
12,680
1
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Originally posted by: TheLonelyPhoenix
Originally posted by: ndee
Originally posted by: Stojakapimp
that the 8 goes on forever, like 7.08888888888

Ah ok. Thanks! The question is, I have to write 7.08888888888... as a breach, how would I do that? 0.8... == 8/9, right?

wtf is a breach?

If that means "fraction", then yes, you would write it as 7 8/9 or 71/9.

ah yes, a fraction, I just translated it in my online dictionary. But how would you write 7.0888888... as a fraction? I know that 0.08 = 8/100 but 0.08(the 8 with a line on it), I have no idea. I have the solution(319/45) but I don't know how to get there, nor do I know how to search for it cuz I don't know how that line is exactly called.
 

So

Lifer
Jul 2, 2001
25,923
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Originally posted by: ndee
Originally posted by: TheLonelyPhoenix
Originally posted by: ndee
Originally posted by: Stojakapimp
that the 8 goes on forever, like 7.08888888888

Ah ok. Thanks! The question is, I have to write 7.08888888888... as a breach, how would I do that? 0.8... == 8/9, right?

wtf is a breach?

If that means "fraction", then yes, you would write it as 7 8/9 or 71/9.

ah yes, a fraction, I just translated it in my online dictionary. But how would you write 7.0888888... as a fraction? I know that 0.08 = 8/100 but 0.08(the 8 with a line on it), I have no idea. I have the solution(319/45) but I don't know how to get there, nor do I know how to search for it cuz I don't know how that line is exactly called.

Yes, the error in the above post is that while .8... = 8/9, .08... != 8/9
 

ndee

Lifer
Jul 18, 2000
12,680
1
0
Originally posted by: So
Originally posted by: ndee
Originally posted by: TheLonelyPhoenix
Originally posted by: ndee
Originally posted by: Stojakapimp
that the 8 goes on forever, like 7.08888888888

Ah ok. Thanks! The question is, I have to write 7.08888888888... as a breach, how would I do that? 0.8... == 8/9, right?

wtf is a breach?

If that means "fraction", then yes, you would write it as 7 8/9 or 71/9.

ah yes, a fraction, I just translated it in my online dictionary. But how would you write 7.0888888... as a fraction? I know that 0.08 = 8/100 but 0.08(the 8 with a line on it), I have no idea. I have the solution(319/45) but I don't know how to get there, nor do I know how to search for it cuz I don't know how that line is exactly called.

Yes, the error in the above post is that while .8... = 8/9, .08... != 8/9

I know, I just wanted to check if I got the 8/9 stuff right :)
 

So

Lifer
Jul 2, 2001
25,923
17
81
Okay, taking the given answer, and windows calculator, we see that 7*45 = 315 and (319-315)/45 = 4/45 = .08...
 

So

Lifer
Jul 2, 2001
25,923
17
81
As for how to take .08.... and convert to 4/45? I can't really remember. Most of these (like 8/9) you just kinda know. For more obscure ones, I use my ti-83 or 89 :D
 

ndee

Lifer
Jul 18, 2000
12,680
1
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Originally posted by: So
Okay, taking the given answer, and windows calculator, we see that 7*45 = 315 and (319-315)/45 = 4/45 = .08...

Yes, I can take a calculator but then, I still don't understand how to get to the x/45 part. Do I just have to try? Or how can I get from 0.08888888... to 4/45?
 

ndee

Lifer
Jul 18, 2000
12,680
1
0
Originally posted by: So
As for how to take .08.... and convert to 4/45? I can't really remember. Most of these (like 8/9) you just kinda know. For more obscure ones, I use my ti-83 or 89 :D

ah ok. Me too but I want to find that out :D
 

So

Lifer
Jul 2, 2001
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I think you can do some sort of infinite series, but that wouldn't make anyone happy.
 

ndee

Lifer
Jul 18, 2000
12,680
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Originally posted by: So
I think you can do some sort of infinite series, but that wouldn't make anyone happy.

It's called "Periodic Line" in German, now I know what to look for :D Thanks anyway!


Found it: you just multiply it by 10 until there are no more commas in the number, like 0.8/9 = 8/90 :D

But now I have another problem, because 0.8 != 0.8... oh well, I will find a solution anyway :) Found it again :D
 

Chronoshock

Diamond Member
Jul 6, 2004
4,860
1
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Yeah you can either just look to see if its something you know thats been scaled or shifted (ie 1/9 -> 1/90 for example) or you can use perturbation:
x = .08888888...
10x = .8888888...
9x = .8
x = 8/90
This works well with all repeating patterns, you just need to do something different for the second term
so for example,
x = .0143143143143...
1000x = 14.3143143143...
999x = 14.3
x = 143/9990
 

ndee

Lifer
Jul 18, 2000
12,680
1
0
Originally posted by: Chronoshock
Yeah you can either just look to see if its something you know thats been scaled or shifted (ie 1/9 -> 1/90 for example) or you can use perturbation:
x = .08888888...
10x = .8888888...
9x = .8
x = 8/90
This works well with all repeating patterns, you just need to do something different for the second term
so for example,
x = .0143143143143...
1000x = 14.3143143143...
999x = 14.3
x = 143/9990

Thanks dude! Makes sense :D