新北师大版四年级数学下册《买文具》课件.ppt

,子页,子页,子页,子页,子页题目,内容：,子页,子页,子页,子页,子页题目,内容：,子页,子页,子页,子页,子页题目,内容：,子页,子页,子页,子页,子页题目,内容：,内容：,子页题目,子页,子页,子页,子页,主页,子页,子页题目,子页,子页,子页,主页,子页,T,H,A,N,K,Y,O,U,*,北师大版 四年级下册 第三单元 小数乘法,问题,探究,练习,拓展,绿色圃中小学教育网,www.L,绿色圃中小学教育网,www.L,铅笔每支,0.3,元,橡皮每块,0.2,元,卷笔刀每个0.7元,尺子每把0.4元,文 具 店,ccccccccccccc,买,4,块,要多少元钱？,0.2,元,0.2,元,0.2,元,0.2,元,买,4,块 多少元？,1.,用加法算式解决：,(),2.,试着列乘法,：,(),这个算式 表示（）,3.,你会计算吗？和同伴交流自己的方法。,自学提示,：,0.2,元,买,4,块,要多少钱？,0.2,元,0.2,元,0.2,元,0.2,元,0.2+0.2+0.2+0.2=,0.2,0.2,0.2,0.2,0.8,0.8,（元）,0.2,0.2,0.2,0.2,0.8,方法二：借助直观模型计算,答：买,4,块橡皮需要,0.8,元。,0.24,0.8,（元）,方法三：用乘法计算,0.2 4,0.2,元,=2,角,2 4=8,（角）,8,角,=0.8,元,0.8,（元）,答：买,4,块橡皮需要,0.8,元。,小锦囊：解决小数乘整数的实际问题，还可以利用单位换算把小数转化成整数再相乘。,买,3,把尺子需要多少元？,0.43,（）,1,2,3,0.4,元,4,角,34,12,（角）,12,角,1.2,元,0.43,1.2,（元）,0.4,0.4,0.4,答：买,3,把尺子需要,1.2,元。,1.2,元,小,结,小数乘整数，与整数乘法的意义相同，就是求几个相同加数的和的简便运算。,1.,买,4,把卷笔刀需要多少元？涂一涂，算一算，,与同伴交流你的想法。,绿色圃中小学教育网,www.L,绿色圃中小学教育网,www.L,绿色圃中小学教育网,www.L,绿色圃中小学教育网,www.L,2.,买,6,支铅笔需要多少元？,与同伴交流你的想法。,3.,0.3,3,0.2,8,4,0.2,3,0.5,0.4,4,0.1,9,0.7,2,6,0.2,0.6,4,3.,0.3,3,0.2,8,4,0.2,3,0.5,0.4,4,0.1,9,0.7,2,6,0.2,0.6,4,0.9,1.5,1.4,1.6,1.6,1.2,0.8,0.9,2.4,7,10,0.7,1,0,7,70,4,6,0.4,6,3,2,0.3,2,来挑战吧！,6,0.6,24,2.4,算一算：,0.7,1=,0.1,5=,0.4,6=,0.3,5=,0.02,4=,0.08,7=,0.7,0.5,2.4,1.5,0.08,0.56,比一比，谁最快,0.8,3=,7,0.5=,1.4,2=,0.7,10=,0.06,5=,4,0.09=,0.01,15=,2.1,4=,2.4,3.5,2.8,7,0.3,0.36,0.15,8.4,5.,1个日记本2.5元，丁丁要买3个这样的日记本，需要多少钱呢？,涂一涂，填一填。,0.0110=,（）,0.1,小练习,涂一涂，填一填。,0.01100=,（）,1,想一想：0.011000=（）,10,拓,展,把一根木条都锯成,0.4,米长的小段，共锯了,4,次，这根木条原长多少米？,