This is neat, but really not too surprising. Because you used the brackets and X for multiplication, I first thought you meant the vector 111x+111y+111z crossed with itself. You really shouldn't do that.
11 * 11 = 121 111 * 111 = 12321 1111 * 1111 = 1234321 .... you get the picture. Please Register or Log in to view the hidden image!
I'm not that much of a math whiz to even know "cross product" vs. product; so I thought it was 12345678987654321. Guess sometimes the simplest answer is the right one, eh?
Hmm...but why? 22*22 gives 484 so the reason perhaps why it doesn't work in larger numbers than 1 is because the number that would follow would be >9 and thus starting to mess up the rest of the numbers... so 222*222 can't give 48(12)84 =) but instead yields 49284 (the "1" in "12" simply adds to the 8, leaving the 2 behind)
Because of the way the ones stack up. 011 011 ----- 11 011 ----- 121 Pretty simple really. Interesting though.
Oh kay Please Register or Log in to view the hidden image!, as you can see in my above example it does work on larger numbers than one, but it scrambles it a bit Please Register or Log in to view the hidden image!
Yes. In fact, 111,111,111 is the highest number it will work with. Add one more one and it screws up the works because you have to start 'carrying the one'.
Mathematics are filled with tons of symetries like this one. Ever heard of the guy who teaches kids how to multiply and divide really large numbers at an amazing speed?
Yes, how does that work? If someone knows, it would be great if you taught us, isn't that what sciforums is all about anyway?
Sorry to disappoint you, but I don't remember how the guy did it.... :shrug: One trick that I do always use when I don't have a calculator is dissecting the numbers, making them all multiples of 10. Like this... 1430= 1000 400 30 Then I do the calculation. For instance, a simple one: 1430 / 2 1000/2 = 500 400/2 = 200 30/2 = 15 sum = 715 Sometimes I do faster shortcuts too. Like this: 1400/2 = 700 30/2=15 sum=715
Also, if you are attempting to calculate numbers that are multiples of 111, you can use 37 multiplications, and raise it by a factor of 3 each time so... 111= 3 x 37 222= 6 x 37 333= 9 x 37 ect. ect. ... ... ... Well, there's my peice anyway.
That's exactly the kind of trick I've discovered one time. While I was watching the Butterfly Effect, for some bizarre reason. That movie makes my brain behave in a very strange manner... :bugeye:
That's nice. When multiplying something *5 like 2398 * 5, you can take (2398/2) * 10 instead. Using your technique together with mine we get: 2000/2 = 1000 300/2 = 150 90/2 = 45 8/2 = 4 2398/2 = 1199 1199 * 10 = 11990 So 2398 * 5 = 11990 Easier example is 5 * 26, it's 130 since 26/2 = 13 and 13 * 10 is 130. This also works when multiplying with *15, like 230 * 15, first you take 230 * 10 which is 2300, then you take 2300/2 = 1150, and add them 2300 + 1150 = 3450, so 230 * 15 is 3450
I remember what was a godsave when i was in primary school. We were always taught that the 9x table had a particular design to it... sure you all know it... we were all taught it at some point... 9x1=9 9x2=18 9x3=27 9x4=36... And each answer would raise the left side by a factor of 1, and the left side would descrease by a factor of 1.
