This works with the number 3 and the number 9.
Is 987659387043185671335 divisible by 9? Add up each digit: 9+8+7+6+5+9+3+8+7+0+4+3+1+8+5+6+7+1+3+3+5 = 108 Add up each digit of that: 1+0+8 = 9.
If you can give me a reason why this works, you're cleverer than I am.
Yes, here is the result
1.097399319×10²?
If you do it my way you don't need a calculator.
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"Okay, okay, I take it back! UnFuck you!"
Sheesh...I worked with a guy who could probably not calculate anything more difficult than 2 x 2 = 4 unless he used a calculator
I presume he really means evenly divisible.
"Mr Macaw" wrote in news: snipped-for-privacy@red.lan:
I'll illustrate the principle using a 3-digit number. Pick any three digits, and designate them as a, b, and c.
The sum of the digits is a + b + c; call this s. The value of the number is (100 * a) + (10 * b) + c; call this v.
The difference between the value of the number, and the sum of its digits, is v - s = (100a + 10b + c) - (a + b + c) = 99a - 9b = 9(11a - b)
Therefore, (v - s) must be a multiple of 9 (and hence of 3 also).
If s is a multiple of 3, and you add a multiple of 3 to it, the result must also be a multiple of 3, and likewise for multiples of 9.
Therefore if s is a multiple of 3 (or 9) then v = s + (v - s) is also a multiple of 3 (or 9).
For a four-digit number abcd, (v - s) = 999a + 99b + 9c = 9(111a + 11b + c) which is clearly a multiple of 9. And so on, for numbers having 5, 6, 7, etc. digits.
Is that in merca?
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5 Brits were injured last year in accidents involving out of control Sca= lextric cars.On Sun, 27 Mar 2016 23:16:52 +0100, trader_4 wro= te:
That's what divisible means.
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Acupuncture is a jab well done.
Hugh betcha
That's what divisible means.
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no.
rote:
Yes. If someone says "12 is divisible by 4", they mean "to produce a wh= ole number". If someone said "13 is divisible by 4" they would be incor= rect.
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If you own a =A33,000 machine gun and a =A35,000 rocket launcher, but yo= u can't afford shoes, you may be a Muslim.
Yes. If someone says "12 is divisible by 4", they mean "to produce a whole number". If someone said "13 is divisible by 4" they would be incorrect.
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no.
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"You just reminded me why my pure maths course at uni made me wish I was in engineering class."
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Indeed. But engineering classes understood what is meant by "evenly divisible" too. It is a pretty basic concept. Like 3rd grade?
Your two references contradict each other. One says that just divisible means it has to be evenly divisible, ie with no remainder. That seems to be the correct definition, multiple source confirm it. So saying evenly divisible is not needed, it's already implied.
Not required in more advanced engineering.
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"Get as far away from the nuclear explosion as possible" - Rodney McKay,= Stargate Atlantis.
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