北師大版數(shù)學(xué)四年級下冊《小數(shù)乘法》課件

小數(shù)乘法DecimalMultiplication北師大版四年級數(shù)學(xué)下冊教學(xué)目標本節(jié)課我們主要來學(xué)習(xí)小數(shù)乘法，同學(xué)們要結(jié)合具體的實例理解并掌握小數(shù)乘法的計算方法，能夠解決相關(guān)的實際問題。Oralcalculation0.34×2=0.1×0.2=0.4×2=2.3×3=0.6×0.4=2.1×10=1.4×0.2=0.5×0.3=1.1×0.2=0.82156×73=40885.6×73=5.6×7.3=13×37=4811.3×3.7=1.3×0.37=根據(jù)第一個算式的積，寫出下面的積．Theproducthasthesamedecimalsasthetwofactors.兩個因數(shù)共有幾位小數(shù),積就有幾位小數(shù).NewknowledgeHereisXiaoMing’sroom.Whatinformationdoyouknowfromthepicture?3.6meters2.8metersXiaoMing’sroomNewknowledgeThelengthis3.6metersThewidthis2.8metersCanyouasksomemathsquestions?

What’stheareaofthisroom?XiaoMing’sroom3.6meters2.8metersNewknowledge3.6×2.8=Whocanestimate(估算)?XiaoMing’sroom3.6meters2.8meters3.6×2.8=3.6×2.8×1036×1028×2887210082887210

08÷10010.08（m）２.Newknowledge3.6×2.8=3.6×2.8×1036×1028×2887210082887210

08÷10010.08（m）２.NewknowledgeOnedecimalOnedecimalTwodecimals3.6meter2.8meter1.15meterWhat’stheareaofthebalcony(陽臺)?1.15×2.8=WhoCanestimate?Newknowledge1.15×2.89202303220TwodecimalsOnedecimalThreedecimals．Newknowledge1、將小數(shù)看作整數(shù)計算。2、根據(jù)兩個因數(shù)的小數(shù)位數(shù)，在積上點上小數(shù)點?？偨Y(jié)：Howdowecalculatedecimalmultiplication?

Canyougivethedecimalpointstothefollowing?.Now,let’sdoexercise.給下面的積點上小數(shù)點。Pleaseworkoutthefollowingproducts.兩個因數(shù)中有一個因數(shù)小于1，積就小于另一個因數(shù)。兩個因數(shù)中有一個因數(shù)大于1，積就大于另一個因數(shù)。在下面的算式中填上“＞”或“＜”。＜＞＞＜已知算式