小数乘法简便计算

201拆成200+1?Р乘法交换律Р4Р=1×4.78  ?=4.78Р0.25×4.78×4Р0.65×201Р=130+0.65?=130.65Р=0.25×4×4.78Р=0.65×(200+1)Р=0.65×200+0.65Р运用乘法交换律Р运用乘法分配律Р5Р用简便方法计算下面各题。Р125×88Р12×25 - 08×25Р15×102Р102×045Р233×05×4Р34×5×6Р25×125×04×8Р6Р用简便方法计算下面各题。Р0.125×8.8Р1.2×2.5 - 0.8×2.5Р1.5×102Р102×0.45Р2.33×0.5×4Р0.034×0.5×0.6Р0.25×1.25×0.4×8Р7Р用简便方法计算下面各题。Р0.125×8.8Р=0.125×8×1.1?=1×1.1?=1.1Р0.034×0.5×0.6Р=0.034×(0.5×0.6)?=0.034×0.3?=0.0102Р102×0.45Р=(100+2)×0.45?=100×0.45+2×0.45?=45+0.9?=45.9Р8Р用简便方法计算下面各题。Р=1.5×100+1.5×2?=150+3?=153Р2.33×0.5×4Р=2.33×(0.5×4)?=2.33×2?=4.66Р=(1.2 – 0.8)×2.5?=0.4×2.5?=1Р1.5×102Р1.2×2.5 - 0.8×2.5Р0.25×1.25×0.4×8Р=(0.25×4)×(1.25×8)?=1×10?=10Р9Р1、应用乘法运算定律填空。Р(1) 7.8×0.8×1.25? =□×( □× □)Р(2)(8+10)×12.5? = □× □+ □×□а(3) 1.7×4.2+1.7×5.8? =□×( □+ □)Р7.8Р0.8Р1.25Р8Р12.5Р10Р12.5Р1.7Р4.2Р5.8Р运用阶段Р10