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Subject: "The number 0.142857....."     Previous Topic | Next Topic
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Conferences The CTK Exchange Middle school Topic #90
Reading Topic #90
Zakatos
Member since Sep-16-03
Dec-02-03, 00:22 AM (EST)
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"The number 0.142857....."
 
   Hello again, thanks everyone for the precious info about my study concerning FPD's (Fully Periodic Decimals, as myself named such elements), I was having trouble to find some time to spend studying more about the subject, but I'll carefully analyze the topic all you pointed me out soon enough.

Meanwhile I noticed something somewhat related to the example I gave you of one of FPD's (the "first" FPD speaking ordinally), 1/7 aka 0,142857.... Notice that this number can be written as the sequence:

7^-2 * 2^1 = 0,14
+
7^-4 * 2^2 = 0,0028
+
7^-6 * 2^3 = 0,000056
+
7^-8 * 2^4 = 0,00000112
+
7^-10 * 2^5 = 0,0000000224
+
...
= 0,142857142857142857...

Any comments? :)



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Zakatos
Member since Sep-16-03
Dec-02-03, 01:26 AM (EST)
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1. "RE: The number 0.142857....."
In response to message #0
 
   Sorry I wrote something wrong. Here it goes:

1 / 7 = (7 * 10^-2 * 2) + (7 * 10^-4 * 4) + (7 * 10^-6 * 8) + ... =

(7*2^1 / 10^2) + (7*2^2 / 10^4) + (7*2^3 / 10^6) + ... =

SUM ( k = 1 to +oo ) OF ( 7*2^k / 10^2k )


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iliaden
Member since Aug-14-05
Nov-05-05, 10:54 AM (EST)
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2. "RE: The number 0.142857....."
In response to message #0
 
   This is great! is this the unique fraction that can be calculated this way, or are there any others?


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