四年级下册小数加减法的简便运算ppt课件.ppt

小数加减法的简便运算,0.70.23 = 10.67 = 5.31.7= 0.75 0.25 =0.750.25 = 0.16 0.24=3.754.2 = 0.90.6= 60.42 = 1.98.1 =,我是神算手,0.70.23 = 10.67 = 5.31.7= 0.75 0.25 =0.750.25 = 0.16 0.24=3.754.2 = 0.90.6= 60.42 = 1.98.1 =,我是神算手,0.93,10,5.58,0.3,7.95,1,3.6,0.5,0.4,0.33,用简便方法计算:,36+11+64+89= 120-37-63=,小数加减法的简便运算,用整数部分是0的小数来凑整,7.2 1.76 2.37 ( ) ( ) ( ) 3.34 0.237 2.178( ) ( ) ( ),0.8,0.24,0.63,0.66,0.763,0.822,分层练习计算下面各题,怎样简便就怎样算,A: 5.78+0.84+0.16 4.13-0.6-1.4 2.23-(1.23+0.86) 9.5+4.85-6.13 B: 3.9+4.08+3.92+1.1 8.07-3.27-0.73-1.07 2.23-(1.23-0.86) 9.5+4.85-6.13,提高练习：判断：,1、4.5+8.3-4.5+8.3=(4.5-4.5)+(8.3+8.3)=0+16.6=16.6 （ ）,3 、 10.7-4.4+5.6=10. 7-(4.4+5.6)=10.7-10=0.7 （ ）,2、6.7+3.8+0.12 =6.7+(3.8+0.12) =6.7+4 =10.7 （ ）,1、小明带了9.5元钱去买学习用品。他买了一个卷笔刀4.6元，一个涂改带3.4元，小明还剩多少钱？,9.5-4.6-3.4,=4.9-3.4,=1.5（元）,9.5-（4.6+3.4）,=9.5-8,=1.5 （元）,答:小明还剩1.5元。,应用练习：,2、下面是一个超市的购物小票。你能算出方框里的钱数吗？,在括号里填上适当的数，使这道题可以进行简便运算。 13.5+4.87+（ ） 16.8-4.56-（ ）,拓展练习,