大同镇泉水沟小学张奋先口算抢答引入课题0.52+0.48=2.8+0.2+5=0.48+0.52=2.8+(0.2+5)=口算抢答引入课题135+39+65+11=134+66+34=计算:0.6+7.91+3.4+0.09=8.51+3.4+0.09=11.91+0.09=12计算:0.6+7.91+3.4+0.09=(0.6+3.4)+(7.91+0.09)=4+8=12验证:计算:5.5+2.7+4.50.38+0.36+2.641.29+3.7+0.71+6.3(1)根据运算定律填空:6.7+□+3.3=6.7+□+4.95(1.38+1.75)+0.25=□+(□+□)练习提高拓展应用(2)计算下面各题,怎样简便怎样算。1.88+2.3+3.75.17+1.8+3.24.02-3.5+0.9813.7+0.98+0.02+4.3练习提高拓展应用小数简算时要注意:一审、二看、三算、四查。综合提高算一算,比一比,你发现了什么?9.3-4.3-0.76.48-(4.48+1)9.3-(4.3+0.7)6.48-4.48-1编码名称数量单价金额10701435面包11.751.7510702312矿泉水10.950.9510702526火腿肠12.052.05应收金额现金5.00交易找零看谁能当上会计师4.750.25编码名称数量单价金额10701434花生油139.5039.5010702537陈醋12.702.7020501525洗发水120.0520.0530912433拖鞋16.306.30应收金额现金100.00交易找零31.45看谁能当上会计师68.55