一年级下册《练习十九》PPT课件.ppt
在做练习十九习题前,回顾内容:1、小括号2、连加连减3、分辨已知条件是否有效,1、35-5+10= 18-(5+3)=2、妈妈买了10个苹果,6个香蕉,我吃了3个苹果,家里还有几个苹果?3、有3箱牛奶,每箱20袋,一共有多少袋牛奶?4、有12块砖,小宁每次搬4块,需要几次能全部搬完?,1.,40,86,45,22,39,64,2.,33,79,37,43,66,58,77,38,3.,17 + 6 + 8 = 43 - 8 - 30 = 60 + 38 - 90 = 50 + 27 - 9 = 54 +(17 + 3)= 93 -(68 - 60)=,31,8,5,68,74,85,96 4 = 92(本),5.,28,68,54,67,63,65,72,25,30,14,18,-4,-4,-4,10,6,-4,2,4个,8.,56 50 = 6(下),9.,38,75,34,0,60,(1)佳佳和小亮一共擦了多少张课桌?(2)你还能提出其他数学问题吗?,12 + 9 = 21(张),小亮比佳佳多擦了几张课桌?佳佳比小亮少擦了几张课桌?,11. 看谁算得都对。,22,15,45,36,16,20,12.,16,8,0,3,7,66,0 0,39,35,16,