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Cool math trick: Converting between miles and kilometers
Here's a very cool trick for using math to convert between miles and kilometers.
Tue, Aug 16 2011 at 11:28 PM
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Photo: Try Stan/Flickr
The Fibonacci sequence is made up of numbers that are the sum of the previous two numbers in the sequence, starting with 0 and 1.
It's 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144…
1 is 0+1, 2 is 1+1, 3 is 1+12, 5 is 2+3, and 8 is 3+5. The number after 144 is 233, or 89+144.
The Fibonacci number describes the golden spiral, an ideal form much beloved by designers everywhere. Interestingly, it also neatly matches the relationship between kilometers and miles. Three miles is five kilometers, five miles is eight kilometers, eight miles is 13 kilometers. It's not perfect, eight miles is actually 12.875 kilometers, but it's close enough in a pinch.
If you need to convert a number that's not on the Fibonacci sequence, you can just break out the Fibonacci numbers, convert, and add the answers. For instance, 100 can be broken down into 89 + 8 + 3, all Fibonacci numbers. The next numbers are 144, 13, and 5, which add up to 162. 100 miles is actually equal to 160.934. Again, close enough.
Math is cool.
Edit: I made a typo on 1+1=3. Thanks to reader Erlinda for catching it.
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"It's not perfect, eight miles is actually 12.875 kilometers"
OMG, you're kidding, right? A 60% error is "close enough"?
The actual conversion is 1.6 miles to 1 kilometer. Here's a thought: instead of screwing around with the Fibonacci series, which obviously doesn't even come close to working, just add half the number of kilos to itself and you'll get a lot closer. 8 km + 4 km = 12 km, which is 94% of the correct value.
"OMG, you're kidding, right? A 60% error is "close enough"?"
OMG, you're kidding, right? The error is in converting 8 to 13, when the actual value would be to convert 8 to 12.875.
"The actual conversion is 1.6 miles to 1 kilometer." actually, NO. 1.6 km equals 1 mile.
8 mi is actually 12.875km, versus the Fibonacci trick's answer of 13km. Error is less than 1%. Quite a bit better than your trick.
Here's a thought: instead of screwing around with halves, which obviously doesn't even come close to working, use the Fibonacci sequence as described. Your method (93 percent accurate, btw, not 94 in this case) has a difference 7 times larger than the Fibonacci sequence.
I don't know where you're getting your 60% error from.
8 miles = 12.875 kilometers. Using the sequence provided, you estimate 8 miles = 13 kilometers. 13 kilometers is a lot closer to the actual value than your method
You are way off- in fact- the opposite is true.
How is 12 closer to 13 than 12.875? This does not make any sense whatsoever. Also, where is this "60%" error you mention?
Hmm.
I do believe you have confused miles and kilometers. If you had read the sentence just before, you would have noticed that she said eight miles would be 13 kilometers. As far as I know, an error of 0.125km does not equal a 60% error. Could you please point out where I made the error, or accept the mistake you made?
why convert. Just learn both or if you only want to learn one, METRIC like 99% of the world.
You guys are all ... WRONG !!!! The easiest way to convert miles to kmh is to go out to your car and read the spedometer...100 kmh = 60 mph ...duh ....... :o<>{
This article made absolutely no sense to me. It starts out as if in the middle of a conversation. There is not even an explanation of who or what Fibonacci is or why this method should be used over others. A little more explanation would have made this a nicer and more useful article for those of us who are clueless about math but still fascinated by it.
By the way, yes, you do discuss Fibonacci AFTER you list the numbers, but the article still left me lost from the very beginning. I've always been terrible at math and am always interested in cool new ways to look at numbers and how they relate to one another, so the article is certainly interesting. Just not especially clear!
Fibonacci FTW. I never knew about this; it's a fun (not efficient, but fun) way to do a boring conversion.
I believe the term is "from my point of view"..... Dug.. :S
Math is NOT cool... please stop trying to make it "fun"
Must be a math hater.
We wouldn't have any of the cool things we have without math. No cool cars, no cool computers, no cool video games, no neat looking buildings or bridges, no cool sports like football, soccer or baseball.
Math is the fundemental upon which all cool is built.
Taxes are not cool
Yes 160 kilometers is 100 miles so he ratio is 1.6 (although Fibonacci is 1.61...ish)
The easiest way to convert, though, is probably...
For miles to kilometers divide by 5 then multiply by 8.
For kilometers to miles divide by 8 then multiply by 5.
Do you have a trick for converting from C to F and back?
Thank You :)
Take your temperature, in either Fahrenheit or Celsius, and add 40. Then multiply by 9/5 to go to Fahrenheit, or 5/9 if you're going into Celsius. Then subtract 40 and you are done. This is a little bit longer, but you only have to remember ONE formula. This works because -40 Fahrenheit is equivalent to -40 Celsius
Forget the fractions. Use 1.8 instead of 9/5. Much easier to remember.
Forget the fractions. Use 1.8 instead of 9/5. Much easier to remember.
Forget the fractions. Use 1.8 instead of 9/5. Much easier to remember.
Wow! 3 X 1.8 Sorry all.
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