智游简算城—小数、整数简便运算练习课学苑街小学:谢屏整数、小数简便运算练习课学苑街小学:谢屏简算城智游口算关口算关8×125=1000口算关口算关8×12.5=100口算关口算关0.8×1.25=1口算关口算关25×4=100口算关口算关2.5×4=10口算关口算关0.25×0.4=0.1口算关口算关24×5=120口算关口算关2.4×5=12口算关口算关2.4×0.5=1.2口算关口算关8×12510008×12.51000.8×1.251﹦﹦﹦25×41002.5×4100.25×0.4=0.1﹦﹦24×5=1202.4×5=122.4×0.5=1.2观察这3组,你能快速计算出来吗?简算厅简算厅25×18×40.25+7.3+0.75142×19+58×193.6×(10+0.1)782-353-34756÷0.7÷0.8说说简算的依据是什么?加法交换律:a+b=b+a加法结合律:(a+b)+c=a+(b+c)乘法交换律:a×b=b×a乘法结合律:(a×b)×c=a×(b×c)乘法分配律:a×(b+c)=a×b+a×c减法的性质:a-b-c=a-(b+c)除法的性质:a÷b÷c=a÷(b×c)简算对对碰简算对对碰2.5×321.5×(125×8)66×2012.5×4×81.5×125×82÷(0.25×0.4)2÷0.25÷0.40.75×(9.9+0.1)0.75×9.9+0.75×0.166×200+1简算小法庭简算小法庭36×0.251.3+1.3×9=9×(4×0.25)=(1.3+1.3)×9=9×1=2.6×9=9=23.42.6×17+2.6×2+2.6=2.6×(17+2)=2.6×19=49.4(√)(×)(×)我是小法官1.3+1.3×9=1.3×1+1.3×9=1.3×(1+9)=1.3×10=13这里的1表示1个几?我是小法官2.6×17+2.6×2+2.6=2.6×(17+2+1)=2.6×20=52这里的1表示什么?简算赛车场简算赛车场3.25-0.48-0.5212.5×25×0.80.15×99+0.1560.8×25-20.8×2536×10.142÷0.7÷0.6简算魔术师简算魔术师(你能写出几种算法)0.9+0.9+0.9+0.9+0.7