设原有x块第一天吃1/2x =>剩1/2x第二天吃1/2x乘以1/2=1/4x =>剩 1/2x-1/4x=1/4x得1/4x=2两边同乘以4x=8所以原来这盒糖有8块
2÷½÷½=8原来这盒糖是8块
设：原来这盒糖是Xx - (1/2)*1/2 x-1/2 x=2x - 1/4 x-1/2 x=2 x=8
2x2x2=8块
