Trick Math Question



18072017, 01:25 AM




Trick Math Question
Without using a calculator, can you figure out the following calculation within 5 seconds ?
999,999,999,999,999,999,999 X 999,999,999,999,999,999,999 = 999,999,999,999,999,999,998,000,000,000,000,000,000,001 We have (21)  9's squared. A friend of mine wasn't the first to discover this, but he saw the pattern recently while playing around with his calculator. So if you wanted to do a nerdy party trick, you could. As it turns out, when you take just about any number of 9's above 9 and square it, you get the same pattern. 99^2=9801 999^2 =998001 9999^2=99980001 999,999,999^2= 999,999,998,000,000,001 Insanity  doing the same thing over and over again and expecting different results 

3 users Like Rahn127's post 
19072017, 02:45 PM




RE: Trick Math Question
Cool.
There's another one along the lines of: 111×111=12321 1111×1111=1234321 11111×11111=123454321 111111×111111=12345654321 The answer is always a palindrome counting up from 1 to the number of 1's you're multiplying. So with 111 x 111, there's three 1's so the answer is 12321. 

19072017, 03:57 PM




RE: Trick Math Question
1 x 142857 = 142857
2 x 142857 = 285714 3 x 142857 = 428571 4 x 142857 = 571428 5 x 142857 = 714285 6 x 142857 = 857142 7 x 142857 = 999999 The digits rotate around up to 6; after 7 you take the first digit and last digit and add them to get the same sequence... 8 142857 1142856 9 142857 1285713 10 142857 1428570 11 142857 1571427 12 142857 1714284 13 142857 1857141 14 142857 1999998 eventually you get to adding the first 2 digits to the last 2, etc Atheism: it's not just for communists any more! America July 4 1776  November 8 2016 RIP 

1 user Likes unfogged's post 
19072017, 04:21 PM




RE: Trick Math Question
I'm a creationist... I believe that man created God. 

19072017, 05:19 PM




RE: Trick Math Question
I learned another one today with the square of numbers that end in 5.
25x25= (2x2)+2 with a 25 on the end. 625 125x125 should equal (12x12)+12 with 25 on the end. 15,625 Insanity  doing the same thing over and over again and expecting different results 

19072017, 07:39 PM




RE: Trick Math Question
(18072017 01:25 AM)Rahn127 Wrote: Without using a calculator, can you figure out the following calculation within 5 seconds ? Too bad most calculators only display 10 digits.... .... I'm a double atheist. I don't believe in your god or your politician. 



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