20以内三连加减混合口算练习题(31).docx

《20以内三连加减混合口算练习题(31).docx》由会员分享，可在线阅读，更多相关《20以内三连加减混合口算练习题(31).docx（56页珍藏版）》请在淘文阁 - 分享文档赚钱的网站上搜索。

1、16-10 + 7=6+5-6=14 + 6-19=19-4-9=15 -4 + 3二20-2- 17=20-4-15 =7+3+3=5+4+4=9 + 6-11=17-11 + 3 =19-9 + 7=7+5+7=19-14+ 5二12-6 + 9=10-8 + 3 =15 + 6-2二18 + 13 - 12 =15 + 13 -11=5+2+1=2+4+1=6 + 14-5 =11 + 15-8=7-7 + 13二6+6+7=18 - 1 - 13=9+1+4=7 + 14-15 =15 - 1 - 11=20-12 + 8=4 + 16-18=12-9-2=13 - 11 + 2=9+

2、5+2=4 + 4 + 12=15 + 14-15 =12-5-3 =7-2+1二13-5-8=4 + 13-9=20-8 + 4二13-1 + 8=4+3-7=20-6-8=4+3-6二19-2-9=5 + 19-5 =2+3+6=18-11 + 5 =6+5-3=6-3+6=4+1+7=8-3+7二11 + 5-6=15 -12 + 3 = 13-8-4=12-9 + 17=13 + 10-7=13 -10 + 16= 2+7+1=19-14-5 =2 + 12 + 3 = 14-2 + 7=17-17 + 20=11 + 4-4=4 + 15 - 15 = 12-5 + 1=3 + 12

3、-5 = 4-3+8二10-8 + 9=12-9 + 4=3+3+4=4 + 18-7=14 + 15-9=6+7-9二5+9+3=20 - 10 - 9=2+6+2=19-1-6=14-1-5 =17-13 + 13 =10-6-4=6-5 + 17=6+4+3=10-4 + 2 =10-1 + 1=5+6-5=14-5 + 8=8+4+7=8-1+1=19 - 16 + 12 =4+4+1=10-2 + 7=11 + 16 - 14=6-6 + 13二2-2 + 15 =17 - 15 + 12 =12 + 5 - 10=10-3 + 6=11 + 19-11 =13 -10 + 2=17

4、-10 + 1=15-8 + 13 =16 + 3 - 13 =13 -10 + 5=16-4 + 7=14-4-3 =10-4 + 10=7 + 11 - 16=11-7-4=6+5+2=3 + 8 + 1=19-2 + 2 =14-8-6=3 + 17-15 =10-6 + 11 =18-4-6=19 -13 - 2=12-5-5 =8 + 11 - 11 =16 + 16-14=13 -13 + 9=16 + 5 - 14=7+9-6=5+1+1=8 + 7-10=8+2-7二3 + 14-12 = 10-1-1=14 + 8-7=9+5+5=11-5-4=9 + 3 - 5 = 14-

5、1-8= 14-1-6=13 + 5-7=20 - 20 + 7=17-2-11=15-4 + 1 =3+6+9=18-4 + 1=2+1+6=6-3 + 11=12 + 12 - 19=8-2 + 11 =15 - 8 + 7=7+2+9=10-7 + 17=17 - 11 - 6二19 - 17 + 13 =6+7+7=8 + 8-13=4 + 6 + 10=19 -17 + 6=8-3 + 13二1+3-2=14-10 + 15 =9-4-4=19 + 12 - 14=11 + 10-3 =3 + 17-18=7+1-6=4 + 10-10=9+1-6=16-5 + 8=12 + 5 -

6、 15 =6+7-1=7-3 + 10=7 + 14-17=19 - 19 + 19=11 + 9-8二10 + 11-5 =19-3 + 1 =18 - 13 + 13 =16-1 + 5 =5 + 6-1二15 + 18-15 =13 + 11-4=2 + 15 - 17=9+4+2=12-5 + 5=15 - 12 + 16=5 -4 + 5二3 + 13 - 16=4 + 16-5 =7+7-4=15 + 5 - 12 =18 -17 + 9=20-1- 18=18-4 + 4=15 + 9-20=6 + 1 + 10=17-5 + 5 =17-8 + 11=12-1-9=16 + 5

7、 - 17=16 + 10-20=20-2-4=15 + 2 - 16=16-15 + 1 =19-7-12 =3+6-7二16-10 + 11 =5+2+2=8-7+8二20 + 10-14=13 - 13 + 19=1 + 19-13 =7-2-2=6+2+7=15-5 + 3=2 + 15 - 15 =14-8-3 =12-6 + 2=2 + 11-7=2 + 16 + 2=20-1-5 =3+7+3=7 + 14-11 =14-8 + 7二11 + 8-2二19-15 + 12 =16 + 13 - 14=6+8-5二9-1-4=11 -5 + 3 =4 + 17-16=5 + 15

8、- 1=6 + 16-6=17-13 + 9=15-2-3 =7 + 5 - 11=8 + 14-13 =16-7-4=3 + 16-13 =20-19 + 12=19 - 17 + 1 =15 - 10 + 13 =20 -11 - 6=19 -19 + 8=14-9 + 6=16-15 + 12=9+5-7二19-11-2=4+2+2=14 + 7-1 =19 - 17 + 18=4-2 + 18=19-4-2 =6-1-3=2 + 4 + 12=6+1-2二15 + 14-12 =1 + 14-2 =17 + 20-17=14 + 1 + 5 =5+5+3=9-2+5=11-9-1 =3

9、+9-9二12 + 2-3 =12-4-6=6 + 13-4=9-3-5=1+8+3=15-6 + 5=12-4-7=7 + 7-10=11 + 9-7=10 + 10-13 =9 + 10-7=16-11 + 1 =5+7-5二11-7 + 11=20 + 5-8=14-13 + 18=9 + 13 - 17=17 + 2-9=19 + 15 -17=13 + 6-18=17 -16 + 7=8 + 15-20=16 + 15 - 13 =12-1-6=4-2+2二13 + 16-17=19-2 + 1=1 + 3 + 10=9 + 11 - 18=18 - 12 + 4 二6-1+8=18

10、 -12 + 8=13 -10-1 =7 + 1 + 11 =8 + 11 - 17=18 - 18 + 15 =18 - 14 - 2=8-2 + 10=9-6 + 12二13+4-6二2 + 14-10二19 -18 + 8=3+ 16 + 1=12 -3 + 10=4 + 16-8=4+6-4=10-2 + 9=2+3+1=18-14-1 =14 + 6-10=17-9 + 10=11 - 10 + 5 =6 + 14-16=20 + 9-16=5 + 16-1=17-9-1=13-6-4=20 -15-4=2+8+6=17 + 8-20=17 + 12 - 17=16-10 + 1=2

11、 + 14-6=20-13 + 11=2+3+3=3+5+6=4 + 12 - 14= 17-7 + 3 =11-3 + 3 =1 + 11-6=12 + 8-15 = 14-2-5二20-9 + 7二2+8+4=17-8 + 3二8 + 13-4= 2+3+4=19 - 13 + 13 =12-1 + 9=17-12-5 = 17-2-7=16-3-1=19-14 + 14= 12-4-8=18 - 11 + 1 =9 + 10-14=7+4+7=16-6 + 5 =13 + 14-17= 7-7+2=16-12 + 12=20 - 13 - 7=15 - 14 + 12= 12-7 + 1

12、5 =19 -17 + 5 =13 + 10-4=10 + 11 - 12=6 + 11 + 2=8 + 10 + 2 =20 - 5 - 11=20-8-11 =13-8 + 8=13-4-9=19-4- 14=7 -4 + 2=20-16 + 15 =18-6 + 7=12-1 + 1=12 + 9-13 =11 -8 + 9=19 - 12 - 2=19 + 7-8=14-4-9=16 + 16-17=12 + 18-11 =14-2 + 3二20 - 12 + 4=7-6+6=10-3 + 5 =16 + 10-14=18 - 16 + 13 =4-3+6=14-7-1 =13-6 +

13、 10=17-1-5 =7 + 14-7=7-7 + 12 =1+6+7=19-8 + 5二2-2 + 20=18-5 + 5 =11 + 2-4=5 + 11 + 3=13-7 + 6二10 + 2 + 2 =6 + 10 + 3 =20 + 2-9=5+1+7=19 - 3 - 14=9+1-9二7 + 13 - 16=18 - 11 + 2=4-1-1=13 + 19-15=11 + 5 + 1=14-2-7=4-1+5二10 + 16-13 =8 + 10-12 =5 + 2 + 11=7 + 11-17=11-8 + 15 =18-3-9=7-2 + 11=9 + 14-20二2 +

14、 10 + 1=15 + 7-6=6+1+7=16-13 + 9=5-3 + 10=4 + 12-9=11 -10 + 8=2 + 17-4=4-1-2=3+3-2二10-4 + 4=6-2-2=11-4-5 =20-13 + 3 =9 + 10-10=19-6-12 =2 + 19-4=7-3+2=15 - 12 + 9=13 - 12 + 16=11 + 4-7=20-17 + 13 =16-6-9=1 + 16-9=15 - 3 + 7二14-9 + 12 =15 - 14 + 17=11 -5 + 12 =1 + 4 + 15 =2 + 1 + 10=19 + 2 - 10=9+2+1

15、=4 + 10 + 3=18 - 1 - 15 =18-5 + 6=8-5-2=11 + 2 - 13 =15 - 13 + 6=2 + 12 + 2 =15 - 12 - 1=14-3-5 =4-3 + 14=13-1 + 5=17 - 11 - 1=5 + 20-18=11 + 6-2 =4 + 11-13 =5 + 11-15 =18 + 3 - 12 =17 + 16-18=8-5 + 12 =19 + 10-10=4 + 14-8=5 + 2 + 13=15 + 12 - 11=14-9 + 8=10-8 + 12 =11-7 + 2 =12-9-1=20 -19 + 8=6 + 1

16、2 - 14=11 + 9-9二19 - 17 - 2=1 + 4 + 14=2+1+8=16-13 + 15 =9 + 14-9=13 - 12 - 1 二5 + 14-11二19-13 + 11=14 + 3-9=7 + 19-7=9-3 + 12 =15 + 2 - 3二17-3 + 4二5-4 + 10=20 - 20 + 18=13-1 + 1=13 -10 - 3=14-6 + 10=7 + 17-14=18-1-8=19-2-7=8 + 18-17=15 - 15 + 7=8 + 14-9=15-2 + 5二10 + 9-3 =8+6+4=14-8 + 3 =17 + 3-1=1

17、9-1-5 =10 + 10-4=10 + 12 - 12 =16 - 13 - 1=13 + 6 + 1=4+5+2=20 + 13 - 13 =8 + 19-18=17-6-3 =19-5-2 =19 - 3 - 15 =10-8-1=20 + 4- 12=12-5 + 9=18-1-6=17-6-8=19-1-4=3-3+8二18 + 13 - 18=19 -17 + 8=17-12 + 2 =11 + 19-19=18-2-3 =13-9 + 15 =14-7-7=3-3+7二3 + 19-20二9-7+2=17-4 + 5 =16 + 10-6=12 + 9-5 =14-9 + 1=

18、2 + 20-6=14-11 + 8=4 + 11-8=15 + 4-1 =8 + 10 + 1=1 + 20-15 =1+6-3二15 + 3-6=15 -4 + 9=7 + 14-20=20-9 + 6=19-2-5 =5 + 11 - 13 =19 + 4-6=2+6+9=11-2 + 8=1 + 5 + 10=20-4-6=8-4-3二5+7+3=7+6+4=11-9 + 16=15 + 6-14=7 + 10-4=14 + 6-1二13 + 2 + 2=14 -1 + 4=20 + 1-13 =15-9 + 2 =5 + 15-2二14-3-7=3+4-3二6+2-8二20 + 9-

19、11 =4+4+4=13 -6 + 12=18-2-12 =19-2-8=19 + 2 - 18=16-2-4=16 + 10-19=3+2+7=13 + 9-9=10 + 12 - 3二9+2-2=11 + 17-17=12 + 8-6=5 + 3 - 5二10 + 6-9=12-8 + 7=7 + 3-10=17 + 7-18=12 + 5-7=17 + 2-4=10-2 + 10=10-4 + 5 =8-6 + 11 =12 + 3 - 15 =5+5+6=9 + 20-12 =10-9 + 17=20-6 + 5 =1 + 9 - 1=8-4 + 10=1 + 4 + 10=16-14

20、 + 16=15-10-4=15-1-8=6-4 + 10=20-2-6=7-6+9二14 + 9-20=12 + 18-12 =5+9+4=20 + 14-16=13-3-7=9 + 14-10=4 + 10-14=17-3-6=19 -13 + 5=17-2 + 5 =13-6 + 2二19 - 12 + 7=11 - 10 + 19=10 + 2 - 10=15 - 14 + 10=4+6+7=1 + 6 + 10=7 + 10 + 3 =3 + 16- 14=17-6-4=18-1-4=5 + 15-18=13 + 3-1=12 + 9-3 =14-14 + 15 =6 + 11-15

21、 =2-2+1=10-2 + 11=15-3 + 1=4+1+9=2+7-1二16-1-12 =14-1-13 =11 + 17-9=20 -17 + 9=4 + 16-6=7-6+4二11-1-6=20 -10 + 2=4-1+6=7 + 20-17=15 - 5 + 2=6 + 10-7=7 + 16-17=5-1-3=10 + 6-8=7 + 16-12 =18 + 6-9=8-8 + 14=18 + 4-10=18 + 2 - 11=11 + 8-6=5 + 18-19=1+9+9=6-6 + 14=12-8 + 10=14 + 14-11 =17 + 2 - 18=3-2 + 12

22、=1+4+2=9-5 + 16=3 + 11 + 4=16-9 + 6=9+7+4=7-2+9二14 + 16-15 =11-4 + 11=5 + 12 - 13 =5+4-4二10-10 + 1=6-2 + 14=19 - 18 - 1=13-4-8=17-8-4=19 - 5 + 5二7+1-1=18 + 11 - 13 =18 -3 + 2 =13-1-6=10 + 4-8=20-5-7=15 - 15 + 19=19-6 + 2 =12 + 15 - 17=20-7-7=14-1 + 6=17 + 5 - 11 =4+7+5=8-3+6二16-12-1 =10-3 + 4二13-9-3

23、 =9+9-7=11-6 + 13 =5 + 9 - 6=10-4-5 =5+4-1=10-2-1 =20-9-9=17 - 11 + 5 =10-4 + 12 =15 - 15 + 20=16-14 + 3 =11 -10 + 7=8-4+6二11-7-1=20-9 - 10=18-16 + 17=8+9-5二14-12 + 17=14-8 + 2 =12 + 9-2 =8 + 19 - 12 =3+6+8=9+1+5=2-1 + 11=20-19 + 5 =17-5-3 =18 -17 + 7=13 - 10 + 6 二15-7 + 10=16 + 10-16=19 -11-4=7-7 +

24、 10=9-1-7=4-2+7二10-10 + 2 =20-16 + 8=14-8 + 9=20 + 2 - 12 =7 + 17-7=11-2 + 9=7 + 10-14=5 + 11-8=16 + 17-19=19-8-8=8-6+8二19-8 + 3二12-4 + 7=10-8 + 8=13-9 + 10=16-11 + 9=18-3-4=19-3 + 3 =5-2+1二14 + 11 - 18=3+6-5=17 + 11-20=12-2 + 5 =5 -4 + 4二9 + 11-10= 9-3 + 10=6 + 13 - 19= 18-16 + 7=16 + 5 - 15=8+6-5二

25、18 - 10 - 1二20 + 3-7=15 + 5 - 17= 8-1 + 12 =11-1-7=9+4-8二 6-1+4=6+5-9二11 + 14-10=5+5-7=1+3+8=15 + 8-3=15 -13 + 11=15-1-6=10 + 11-3 =11 + 6-6=5 - 1 + 9= 7-6 + 16=19 - 19 + 4= 17-6-5 =5 + 12 - 14=6+9+2=11 -6 + 11 =11-8 + 16=17-1 + 3 =5+4+1=13-3 + 6=16-3-8=14 + 16-16=2+2-3=1+9+2=7 -1 + 11=13 + 12-9=18

26、- 15 + 17=1+1+3=13-3-2 =4+4+9=7 + 20-8二6-5+8=8+5+2=9 + 11 - 15 =5 + 17-19=15 + 1-6=18 + 11-14=9-3+9=19-15-3 =20 - 20 + 19=8+5-9二15-2-5 =1 + 15-4=13-1-8=12 + 8-18=8-8+3=17-7-1 =6+1+2=18-13 + 10=17-11 + 8=20-8 + 2 =18-5-7=15 - 14 + 6=13-4 + 11 =20-3-2 =7+5-9=19 + 7-17=19 - 5 - 13 =14 - 13 - 1=3 + 19-2

27、 =15 - 12 + 10=10-4 + 8=15 + 9-6=18 + 5-7=15 - 10 - 2=2 + 17-5=8 + 3 + 1=9 -8 + 13 =16 + 13 - 12=11 + 11-7=2 + 12 - 14=14 + 6-13 =17-6-9=11 + 10-8=8+2+7=16-13 + 13 =2-2 + 18=7+4+8=12-3-6=16-10-3 =15 - 11 + 9=2 -1 + 15 =16-6-3 =17 -14 + 8=6-5 + 13 =6 + 18-13 =6 + 10 + 2 =2 + 16-18=2+4-3二1+8-5二9-1-1=1

28、2 + 7-3 =11-9 + 13 =20 - 20 + 14=16-9-4=12 + 10-6=15-11-2=19-5- 12 =19 - 19 + 15 =13-6-1=2 + 18-13 =17 - 1 - 15 =14-4-6=16-10 + 13 =15-10-1=12 + 3 + 1 =17 + 14-11 =3 + 3 + 11=20-7 + 2 =12 + 4-5 =13-4 + 9=14 + 1 + 2=2 + 7 + 10=6-2+2二20-3-1=18 + 20-18=20 - 14 - 2=20 - 16 - 3=5 - 3 + 15 =18-9-2 =6-4 +

29、14=4+8+2=15 - 13 + 9=13 -4 + 4二2+2+5=3+6+2=1+8+8=17-9 + 7=18-8 + 1=14-10 + 7=4-1+8=4 + 10-5 =6+1-7=8-3-5=15 - 1 - 14=15 + 1-4=16 - 14 - 2=19-6-6=15 - 15 + 2=20-6-3 =4+6+1=5 -1 + 2 =14-4 + 6=12 + 16-11=7-5+1=6-3-3=19 + 8-16=1 + 10 + 5 =7-4 + 12二13 -12 + 14=13 + 5 + 2=11 + 10-16=12-6 + 1 =16-2-9=7 + 1

30、1 + 2=5-5+5=18 -12 + 1 =12 +16 -16=19-3-8=12 + 6-11 =6+7-5二12 -5 + 12 =19 + 4-9二2+8-9二16-12 + 5 =16-5-7=12 + 3-9=2 + 19-20二11-3-5 =20-13 + 4=18 + 7-9=13 + 7-10=19 + 16-16=3 + 13-6=17 + 17-19=14 + 2-3 =5+1+3=8 -4 + 3二12 + 12 - 11=14-11 + 13 =12 + 12 - 15 =20-7-12 =3 + 11-2 =16 + 4-16=15 - 2 - 13=9-9+

31、5=3 + 11 - 11=20 + 1-3 =11 + 8 + 1=4-3 + 18=20-9-3 =16-7 + 7=1+4+8=18-4-9=2+2+4=13-1-3 =19 - 12 - 3二20-17 + 12=6+2+2=13-7-6=16-11 + 5 =12 + 7-19=20-18 + 8=14-7 + 4二4 + 15 - 19=20-14 + 14=13-6 + 8=5 + 17-10=9+8+2=11 + 17-16=12 + 6-12 =16-16 + 15 =16-15 + 7=5 + 19-12 =17-7-9=16-14 + 8=20-4-9=7+9+2=20-

32、16 + 10=19-10 + 3 =18 + 4-8=19 + 17-20= 14-8 + 12 =4 + 11 - 5二17 + 14-13 =20 + 2-5 =15 + 3 - 18=20 + 3 - 20=11-7 + 4=4 + 14 + 2 =17 + 1-8=20-3-5 =19 + 13 - 13 =13 + 9-13 =19 + 6-9=17-7 + 10=11 + 13 -16= 18-4-13 =9-3+6二19 + 6-7=5 + 13 + 1=14 - 12 - 2二15 - 15 + 3=18-9 + 4=16-5 + 5=3 + 14-10=19 + 8-13

33、=14 + 20-15 =5 + 3 + 11=12 -8 + 12 = 10-9 + 3 =11 + 3 + 6= 16-5-9=15 + 2-6= 1+7+9=11 + 13 - 14=12 + 7-5 =10 + 2-2 =6-4+3=19-16 + 4=7+1-8二20-16 + 4=14-11 + 5 =5+3+6=15-3-6=1+7+8=16-6 + 3=6 + 15 - 14=7 + 16-18=14-5-1=5+6+5=3+7-3二7+8+4=17-12 + 15 =12 + 12 - 5 =2 + 15 - 14=11 + 1 - 12 =9 + 19-19=2+9+5=7

34、 + 17-20=19-11 + 3 =7+8-6二8+8-4=11-2 + 3 =8 + 10-11=15-7 + 6=11 - 10 + 17=20 + 11 - 16=4+3+9=17-16 + 6=5-5 + 10=12 + 6-16=18 - 17 + 4=15-3-8=17-3-8=19-8 + 9=20-3-15 =5 + 13-6=9 + 19-20=16 + 6-14=18 - 16 + 2=19-15 + 6=14 + 4-8二18-1- 16=19 + 14-18=19-7-6=6+9+3=8+6-4=18 -11 + 9=I + 13 + 1=10-1 + 4=8+7-

35、5二20-7 + 4=9-4+3=9-9 + 16=17-8-5=II -1 + 2 =14 + 3 + 1=12 + 19-15 =16 + 6-3二14 + 9-6=3+8+6=8 + 20-16=8+8-5=14-12 + 12 =17 + 9-6=17 - 15 + 2 =20-14 + 6=7 + 9-13 =13 - 11 + 8=5 + 18-12=8 + 12-7=10 + 7 + 2=20 - 15 - 1 =3+3-5=6+5+4=20-11 + 6=13 - 13 + 10=18-18 + 20=18 + 2-4=9-8-1=13 -12 + 15=20 + 8 -17=

36、7+3+6=18 -13 + 4=15 -12 + 17=5 + 12 - 11=13 + 5-4=11 + 16-18=15+4-11=16-3-6=5 + 10-7=8-1-6=9-1 + 10=4 + 15-4=15-7-6=12 + 9-18=15 + 12-7=11 - 11 + 10=19 - 12 - 7=15-8 + 12 =15 + 2 + 1=2 + 14 + 3 =13 + 14 - 14=3+7-8二19 + 6-14=14-13 + 8=3+5+4=20-16 + 11=12 + 11-19=2 + 20 - 20=16-12 + 16=20-18 + 4=9-6 +

37、 16=6+6-4=10-3 + 13 =16-1-4=14 + 5-1=20 + 7-12=6-5 + 11 =18-1 + 3 =18-5-3 =15 - 6 + 7二7 + 13 - 11=9-3+7二17 + 6-16=19 + 2-1 =16-6 + 9=13 + 5 - 16=8-6+6=19 - 18 + 12 =2+9+3=16 + 15 - 19=9-1+2=16 - 3 -11=17-16 + 18=8 + 18-15 =6+2+4=4-1 + 17 =8-5+3=2 + 8-10=11-7 + 6=4 + 13 - 13 =8+2-2二13 + 5-8=17-13 + 6

38、=12 - 11 + 18=14 + 4-2 二19-3-9=18 -11 - 7=17-6-2 =8-7+4二12 - 10 + 18=12 - 1 - 10=18 - 3 - 12 =13 - 10 + 14=7+9+4=16-7 + 2 =19 - 11 + 6=19 - 13 - 1=16-7 + 6=6-1 + 13 =16-6 -10=15 - 13 + 4=13-5-3 =3 + 10 + 6=5 - 5 + 13 =8 + 1 + 11 =16-5- 10=1+5+2=17 + 16-13 =5-3+8=20-5-5 =16-5-5=14-7-6=13 -5 + 4=5 + 1

39、3 - 16二19-9- 10=5 + 10 + 1 =16 + 12-9=5-2+5=15-11-3 =10-7 + 10=9+8-9二20 - 15 + 10=17-4-13 =16 + 18-15 =20-11 + 5 =13 -5 + 11=17 -11 + 9=20-2- 14=19-2-11=14-14 + 20=19 -13 + 1=15-4 + 5 =13 + 1 + 3 =5-5 + 16=17 + 14-14=20 + 14-14=20-7-3 =15-7-8=2-1+5=9-1-8=18 + 16-20=15 + 13-20=10 + 9 + 1=11 + 15 - 10

40、=16-4 + 6=1 + 1 + 17=8+2+2=8 + 2-10=5-4 + 12 =14-11 + 2=8-1-2=19-3-7=17-16 + 14=4 + 18-8=4 + 19-5二12-6 + 7=19-1- 12 =6 + 2 + 10=9+7-9二9-5+4二15 + 13-9=18-14 + 1=20 + 4-16=13 - 3 + 10=3-2+8=15 - 10 + 4=19-16 + 5 =8 + 11-8=9+4+5=16-16 + 13=1 + 8 + 10=10-3 + 7=14-6-7=10 + 17-18=20-19 + 18=9+7+1=8-3-3=7+

41、2+7=8+1-6=7+2+4=17-4 + 1=8-3+9=5+3-7二3 -1 + 3 =5 - 5 + 2 =9-8 + 11=1 - 1 + 8二2+7+4=8 + 4- 10 二9-1+1=13 + 10-16=15 - 3 + 5 =5 + 3 + 12=19 - 10 - 8二9 + 14-15 =15 - 8 + 1=15 - 11 + 14=8-8 + 15 =15-3-2 =20-3-7=16 + 4-8二16-1-6=3-2+2二8 + 11 - 14=18-13-2 =9-5-2=10-6 + 6=17 + 11 - 13 =13-9 + 13 =9-6-2=4+2+3=1 + 10 + 1 =16-1-13 =3+9+6=15-1-5 =12 + 15 - 8=11 + 10-10=13 + 16-14=13-6 + 6二16-3-9=7+5+2=20 + 2 - 18=9+1+7=17-2