999.3—998.2+997.3—996.2+………+3.3—2.2+1.3—0.2
=(999.3—998.2)+(997.3—996.2)+………+(3.3—2.2)+(1.3—0.2)
=1.1+1.1+...+1.1+1.1(共有500个1.1)
=500×1.1
=550
不懂的再追问.
999.3—998.2+997.3—996.2+………+3.3—2.2+1.3—0.2
=(999.3—998.2)+(997.3—996.2)+………+(3.3—2.2)+(1.3—0.2)
=1.1+1.1+...+1.1+1.1(共有500个1.1)
=500×1.1
=550
不懂的再追问.