新青岛版四年级数学下册玩转口算Word文件下载.docx

1、 172584228 = （172） （ 42） 三、开放练 算一算，填一填。（1）你发现了什么规律？（2）你能用含有字母的式子表示这个规律吗？（3）用上面的规律计算下面各题。45823268 763（263179）28618812 36959416931698 5691034520= 0999732=205= 1250=1225= 45254=4= 433=9425= 256237 1258= 58=74= 125（48）=958= 3252=7925= 435=23 502= 1251324= 4125=1025= 51713 538= 25（2511）4= 566756二、变式练。1、填

2、一填。354=35 （3725）4 = 37（） （ab）c = a （92115） 85 = 92（85） （1004） 25 = （ab） = cc （482） 50 =48 125）=125801254 120101 = 120（10）53x=a（53 ）2、连一连。三、开放练 1、算一算，填一填。 3224 1000425 450（53） 1000（1025） 130001258 54045 2、运用简便方法计算下面算式。 56101 4825 997676 9837 （808）125 8810188一、基本练0.1+0.9= 0.1+0.8= 0.7+0.7= 0.9+0.8= 0.

3、9+0.9= 0.1+0.4= 0.1+0.3= 0.1+0.2= 0.9+0.2= 0.8+0.2 0.7+0.2= 0.6+0.2=0.5+0.2= 0.4+0.2= 0.3+0.2= 0.3+0.2= 0.2+0.2= 0.9+0.3= 0.8+0.3= 0.7+0.3= 0.6+0.3= 0.5+0.3= 0.4+0.3= 0.9+0.4= 0.8+0.4= 0.7+0.4= 0.6+0.4= 0.5+0.4= 0.4+0.4= 0.9+0.5= 0.8+0.5= 0.7+0.5= 0.6+0.5= 0.5+0.5= 0.9+0.6= 0.8+0.6= 0.7+0.6= 0.6+0.6

4、= 0.9+0.7= 0.8+0.7= 二、 变式练5.1+4.9= 5.2+4.8= 5.3+4.7= 5.4+4.6= 5.5+4.5= 5.6+4.4= 5.7+4.3= 5.8+4.2= 5.9+4.1= 4.1+5.9= 4.2+5.8= 4.4+5.6= 4.5+5.5= 4.6+5.4= 4.8+5.2= 3.1+6.9= 3.2+6.8= 3.3+6.7= 3.4+6.6= 3.5+6.5= 3.6+6.4= 3.7+6.3= 3.8+6.2= 3.1+6.9= 2.1+7.9= 2.2+7.8= 2.3+7.7= 2.4+7.6= 2.5+7.5= 2.6+7.4= 2.8+

5、7.2= 2.9+7.1= 6.1+3.9= 6.2+3.8= 6.3+3.7= 6.4+3.6= 6.5+3.5= 6.6+3.4= 6.7+3.3= 6.8+3.2= 6.9+3.1= 7.1+2.9= 7.2+2.8= 7.3+2.7= 7.4+2.6= 7.5+2.5= 7.6+2.4= 7.7+2.3= 7.8+2.4= 7.9+2.1= 8.1+1.9= 8.2+1.8= 8.3+1.7= 8.4+1.6= 8.6+1.4= 8.7+1.3= 8.8+1.2= 8.9+1.1= 9.1+0.9= 9.2+0.8= 9.3+0.7= 9.4+0.6= 9.5+0.5= 9.6+0.4

6、= 9.7+0.3= 9.8+0.2= 9.9+0.1= 1.1+8.9= 1.2+8.8= 1.3+8.7= 1.4+8.6= 1.5+8.5= 1.6+8.4= 1.7+8.3= 1.8+8.2= 8.6+1.5=三、开放练0.87+0.2 1.40.6 6.83 5.9+0.2= 4.7+0.4= 6.3+1.8= 6.8+3.3= 8.5+4.6= 10+2.4= 11+3.4= 13+6.4= 16+4.7= 14+8.7= 15+3.2= 6.9+3.2= 5.8+6.7= 4.9+8.7= 2.8+3.5= 3.9+6.7= 5.9+4.8= 6.3+8.9= 5.6+2.8=

7、4.7+5.9= 8.5+3.3=7.9+6.4= 4.3+6.8= 5.2+3.9= 4.7+3.1= 3.8+0.4= 5.9+1.5= 2.2+3.9= 3.3+1.8= 3.4+2.7= 4.6+1.5= 4.7+2.4= 5.3+4.8= 9.6+2.3= 8.2+3.3= 6.5+4.7= 9.8+2.4= 8.6+5.5= 1.9+8.7= 14+3.5= 16+4.8=0.9-0.1= 0.8-0.1= 0.7-0.1= 0.6-0.1= 0.5-0.1= 0.4-0.1= 0.3-0.1= 0.9-0.2= 0.8-0.2 0.7-0.2= 0.6-0.2= 0.5-0.2=

8、 0.4-0.2= 0.3-0.2= 0.9-0.3= 0.8-0.3= 0.7-0.3= 0.6-0.3= 0.5-0.3= 0.4-0.3= 0.9-0.4= 0.8-0.4= 0.7-0.4= 0.6-0.4= 0.5-0.4= 0.9-0.5= 0.8-0.5= 0.7-0.5= 0.6-0.5= 0.9-0.6= 0.8-0.6= 0.7-0.6= 0.9-0.7= 0.8-0.7= 0.9-0.8= 0.9-0.9=5.1-4.9= 5.2-4.8= 5.3-4.7= 5.4-4.6= 5.5-4.5= 5.6-4.4= 5.7-4.3= 5.8-4.2= 5.9-4.1= 4.1

9、-5.9= 5.8-4.2= 5.7-4.3= 5.6-4.4= 5.5-4.5= 5.4-4.6= 5.3-4.3= 5.2-4.8= 5.1-4.9= 6.9-3.1= 6.8-3.2= 6.7-3.3= 6.6-3.4= 6.5-3.5= 6.4-3.6= 6.3-3.7= 6.2-3.8= 6.9-3.1= 7.9-2.1= 7.8-2.2= 7.7-2.3= 7.6-2.4= 7.5-2.5= 7.4-2.6= 7.2-2.8= 7.1-2.9= 6.1-3.9= 6.2-3.8= 6.3-3.7= 6.4-3.6= 6.5-3.5= 6.6-3.4= 6.7-3.3= 6.8-3.

10、2= 6.9-3.1= 7.1-2.9= 7.2-2.8= 7.3-2.7= 7.4-2.6= 7.5-2.5= 7.6-2.4= 7.7-2.3= 7.8-2.4= 7.9-2.1= 8.1-1.9= 8.2-1.8= 8.3-1.7= 8.4-1.6= 8.5-1.5= 8.6-1.4= 8.7-1.3= 8.8-1.2= 8.9-1.1= 9.1-0.9= 9.2-0.8= 9.3-0.7= 9.4-0.6= 9.5-0.5= 9.6-0.4= 9.7-0.3= 9.8-0.2= 9.9-0.1= 8.9-1.1= 8.8-1.2= 8.7-1.3= 8.6-1.4= 8.5-1.5=

11、8.4-1.6= 8.3-1.7= 8.2 -1.8= 8.1 -1.9= 7.9-0.9= 8.2-0.8= 9.3-0.4= 9.2-0.5= 8.7-0.5= 8.6-0.8= 9.5-0.7= 1-0.6= 4-0.3= 2-0.4= 5-1.3= 6-2.4= 7-3.6= 8-4.2= 9-4.7= 12.5-2.5= 14.7-4.7= 16.8-4.2= 14.8-3.2 = 10-0.8=15.6-5.2= 10-0.6= 10-0.7= 10-1.5= 10-2.3= 10-4.8= 10-5.7= 10-6.9= 13.4-3.2= 9-1.7= 6-1.3= 14-1.

12、8=0.210= 0.0310= 1.5310= 2.4810= 3.0410= 1.510= 3.1610= 2.40430.510= 42.910= 2.00810= 2.008100= 2.0081000= 12.710= 0.6510= 0.028.5310= 1210= 3.610= 24510= 304100= 500710= 30201000= 15.710= 57.310= 49.8100= 302.810= 405.7100= 3.210= 12.510= 45.6100 3.571015.7100= 12100= 3 .6100= 12.7100= 3.16100= 0.03100= 1.5100= 0.2100= 4.9100= 12.8100= 4.16100= 0.203100= 2.071000= 0.08100= 20.09100= 31.681000= 0.08100 = 6.235100= 1.257100= 12.71000= 1000= 121000= 3651000= 3.612.71000= 3.161000= 1.51000 = 0.031000= 0.21000= 12.81000= 4.91000= 2.0510= 2.061000= 18.011000= 4100= 8100=