I dont know how this does it but it picked my number correct 6 times in a row...
http://www.break.com/index/pick_a_number.html
http://www.break.com/index/pick_a_number.html
whenever you subtract the sum of the digits from a 2 digit number you get a multiple of the number 9.tnickp said:thats pretty messed up! i'd be very curious to know how that works. i tried 10 times, all different numbers!!! craziness
Obviously failed grade 11 math...because there are no 2 digit numbers that when the sum of the digits are subtracted from that number equal 90.Feef said:whenever you subtract the sum of the digits from a 2 digit number you get a multiple of the number 9.
ie 9, 18, 27, 36, 45, 54, 63, 72, 81, 90
Feef (and I failed grade 11 math!)
A simple proof:Feef said:whenever you subtract the sum of the digits from a 2 digit number you get a multiple of the number 9.
...
Why u hurta my brain like dis?dax said:If "a" and "b" are the numerals of a two digit number "ab"
ab can also be expressed as 10 times a ("a" is in the "tens" column) plus b or
10a +b
adding the two digits is a + b
subtracting the sum of the digits from the original number is
10a + b - (a + b) = 10a - a + b - b = 9a (by definition a multiple of 9)