小數乘法簡便運算課件

小數乘法的簡便運算五年級小數乘法的簡便運算五年級1小數乘法簡便運算課件2小數乘法簡便運算課件3比較一下,哪邊的計算更簡便.(3.2＋2.8)×0.63.2×0.6＋2.8×0.61.25×23×0.81.25×0.8×23小數整數比較一下,哪邊的計算更簡便.小數4下面計算運用了什么定律.(1.25+2.5)×0.8=1.25×0.8+2.5×0.82.5×3.2×4=3.2×(2.5×4)填空:0.25×8.9×4=0.25×()×()3.2×2.8-3.2×0.8=3.2×(-)9.2×1.01=9.2×()+9.2×()4.1×0.99=4.1×()-4.1×()下面計算運用了什么定律.填空:5小數乘法簡便運算課件612.5×0.43×82.5×1.25×325.6×1.3＋5.6×8.72.5×(40＋0.4)3.2×99＋3.23.2×1.017.2×10.2－7.2×0.27.2×(10－0.1)7.2×101－7.20.61×9912.5×0.43×87口算:1.25×80=5×0.6=0.6×0.08=1.2×5=20×0.05=4.3×2=3.5÷10=0.21÷3=口算:8口算:1.25×80=1005×0.6=30.6×0.08=0.0481.2×5=620×0.05=14.3×2=8.63.5÷10=0.350.21÷3=0.07口算:97.1×1.017.10.43×0.990.993.5×0.633.57.1×1.017.110比一比,誰算得又對又快:4.05×233.2×0.7562.4÷610.88÷6411.5÷46比一比,誰算得又對又快:112.5×0.99=2.5×100－0.01=250－0.01=249.992.5×0.99=2.5×1－2.5×0.012.5×0.992.5×0.99122.5×20.1=2.5×20＋2.5×1=50＋2.5=52.52.5×20.1=2.5×20＋2.5×0.12.5×20.12.5×20.1131.25×2.5×32=1.25×8＋2.5×4=10＋10=201.25×2.5×32=(1.25×8)×(2.5×4)1.25×2.5×321.25×2.5×32142.5×4.8=2.5×5－2.5×0.2=12.5－0.5=122.5×4.8=2.5×4×1.22.5×4.82.5×4.815小數乘法簡便運算課件16小數乘法的簡便運算五年級小數乘法的簡便運算五年級17小數乘法簡便運算課件18小數乘法簡便運算課件19比較一下,哪邊的計算更簡便.(3.2＋2.8)×0.63.2×0.6＋2.8×0.61.25×23×0.81.25×0.8×23小數整數比較一下,哪邊的計算更簡便.小數20下面計算運用了什么定律.(1.25+2.5)×0.8=1.25×0.8+2.5×0.82.5×3.2×4=3.2×(2.5×4)填空:0.25×8.9×4=0.25×()×()3.2×2.8-3.2×0.8=3.2×(-)9.2×1.01=9.2×()+9.2×()4.1×0.99=4.1×()-4.1×()下面計算運用了什么定律.填空:21小數乘法簡便運算課件2212.5×0.43×82.5×1.25×325.6×1.3＋5.6×8.72.5×(40＋0.4)3.2×99＋3.23.2×1.017.2×10.2－7.2×0.27.2×(10－0.1)7.2×101－7.20.61×9912.5×0.43×823口算:1.25×80=5×0.6=0.6×0.08=1.2×5=20×0.05=4.3×2=3.5÷10=0.21÷3=口算:24口算:1.25×80=1005×0.6=30.6×0.08=0.0481.2×5=620×0.05=14.3×2=8.63.5÷10=0.350.21÷3=0.07口算:257.1×1.017.10.43×0.990.993.5×0.633.57.1×1.017.126比一比,誰算得又對又快:4.05×233.2×0.7562.4÷610.88÷6411.5÷46比一比,誰算得又對又快:272.5×0.99=2.5×100－0.01=250－0.01=249.992.5×0.99=2.5×1－2.5×0.012.5×0.992.5×0.99282.5×20.1=2.5×20＋2.5×1=50＋2.5=52.52.5×20.1=2.5×20＋2.5×0.12.5×20.12.5×20.1291.25×2.5×32=1.25×8＋2.5×4=10＋10=201.25×2