四年级数学《小数点的加减法》教学课件维语.ppt

,先学后教,0.8，0.207，0.0012，,2.3，12.608，300.168,0.6，0.49，6.064，10.168，,0.333，2.3043043043.14159265,1.,2.,.,3.,.,2004,10,17,352.14,10-.,国优秀运动员刘翔在2004年雅典奥运会上勇夺110m跨栏金牌，成绩是12.91s,51 21 28 100 36 38 36 110 23 21 28 72 19 13 15 47,2004,10,53.40,49.80,3.6,10,53.4049.80？,3.6,5 3.4 0,4 9.8 0,0,6,3,.,:,0 0.,53.40,49.80,58.20,49.20,10,53.40+58.20？,111.6,5 3.4 0,+,5 8.2 0,0,6,小数点要对齐,1,.,1,1,:,0 0.,53.40,49.80,58.20,49.20,10,53.40,49.80,58.20,49.20,82.80,71.04,86.70,327.78,352.14,76.60,76.70,75.48,10,12.424.36,7.813.735,12.424.36,7.813.735,0,0,.,0 0,.,3.6+1.4,5.7-2.3,7.6-3.1,4.9+0.5,6.2-2.4,4.9+1.5,0.26+0.35,0.93-0.58,0.37+14.3,65.8 12.6,50 8.35,8.52,(,.,.,),4.75+3.4=4.75+3.40-4.75+3.4-,2.37+0.63=3.001.56+0.8=2.361.2-0.87=0.3310-2.04=7.963.427-3.418=0.0094.56+5.44=10.00,