I need a math trick/game for my math course......something that can be proven with a fairly simple proof.....Ive looked everywhere and most of teh stuff is logic problems...(which have ridiculously complex proofs...) it can be a card trick/dice/dominoes but again, not too in depth. This is for a college course but she said we can do even a kids math trick as long as its proven. Any suggestions/websites would be great....Ive done so much research already!!! arrrghhghh
2007-01-30 04:26:56 · 2 answers · asked by Drea 2 in Science & Mathematics ➔ Mathematics
How about this:
Pick any number (well, almost any. less than 2,222,209 & positive let's say.)
Add 14
Multiply by 9
Subtract 8
Add up all the digits
Add 5
Add up all the digits again
Subtract 6... You now have the number zero regardless of what number you picked first.
x
x+14
9x + 126
9x + 118
sum of digits of (9x + 118) ≡ 9x + 118 ≡ 1 (mod 9) *
1 + 5 = 6 (mod 9)
6 - 6 = 0
*You may be required to prove that the sum of the digits of a number mod 9 is the same as the number mod 9
2007-01-30 05:25:28 · answer #1 · answered by Scott R 6 · 2⤊ 0⤋
www.pekiyi.150m.com
NAIM x NAIM = FINDNAIM
Answer:
NAIM=9376
2007-01-30 12:40:08 · answer #2 · answered by iyiogrenci 6 · 0⤊ 2⤋