被除数÷除数=商被除数÷商=除数除数×商=被除数被除数÷除数=商除数×商=被除数乘法和除法是互逆的运算。(12)(3)?(3)___(12)4(12)(3)4§2.8有理数的除法(18)6(27)3(16)4=1(2)=218(6)27(3)16(4)=12()=2(18)(6)(27)(3)(16)(4)=1(2)()=2-3-9-4-4-3-9-4-43944例1:(15)(3)112()4(0.75)0.251(12)()(100)1212(2)3练习:(0.26)0.26(16)(2)(378)7(9)06?0(6)?21()530.8()1011()()4602(1)53(0.8)1011()4605(1)2410()531(60)452831521()530.8()1011()()46052831551()2100.8()31()(60)452831512()50.8()0311(6)4)1(052831515()23.8()010(1(6)0)45283152(18)()3例2:4916()()38课本P56,习题2.12