食堂里原有大米42袋，用去27袋， 又买来40袋， 现在有多少袋大米?-b(R1m:X/W:w/N*i.t
算式：提示-l3L7D,W-b(R1m:X/W:w/N*i.t
答：现在有大米9x4Y,Q/]-p6o9`袋。-b(R1m:X/W:w/N*i.t