首先每人係心裏面想一個三位數,三個數字要不同的,然後再將那三位數倒轉,看看那一個較大,把大的減去較小的.然後你會得出一個兩位數或三位數,如果是兩位數也看作三位數,而百位是零.例如99則看作099. 然後把數字倒轉再相加.例099+990. for three distinct a,b,c 一個三位數(三個數字要不同的)can be represented by 100a+10b+c and denote it as A the reverse of 100a+10b+c be B B=100c+10b+a suppose A>B A-B=99(a-c) the possible cases for a-c can be 1,2,3,4,5,6,7,8,9 by checking that all of them multiplicity 99 and follows the rule that “然後你會得出一個兩位數或三位數,如果是兩位數也看作三位數,而百位是零.例如99則看作099. 然後把數字倒轉再相加”