《20以内加减法口算练习题(115).docx》由会员分享，可在线阅读，更多相关《20以内加减法口算练习题(115).docx（61页珍藏版）》请在taowenge.com淘文阁网|工程机械CAD图纸|机械工程制图|CAD装配图下载|SolidWorks_CaTia_CAD_UG_PROE_设计图分享下载上搜索。
1、15 + 4=4 + 2 =6-2 =9 + 1=11-4=17-8=12 - 10=19 - 10=13-8=14 + 4=8-4=12 - 11=9 + 4=6 + 7=9 + 2 二4 + 4二16-3 =19-1 =2 + 13 =10 + 10=4 + 14=12 - 3二15-7=17-6=10 + 5 =4-1二18 - 17=4 + 15二2 + 16=5 + 12=13-7=20-6=18-2 =6 + 14=12-2 =6 + 9=18-3 =13 + 1=4 + 13二13 -10=1 + 5=8 + 1=8 + 6=8-3 =4 + 10=15-9=5-3 =14 -
2、11 =15 - 12 =18 - 10二1 + 2=13 + 4=10-5 =20-11=7 + 7=11-2=14 + 6=16-8=9 + 9=8-8=7 - 1=3 + 12 =2 + 8 二20-5=5 + 10=20-9=9 + 5 =5 + 11 =18 + 1=9-7=15 + 2=17 - 14=19-11=20 - 20=16-5 =11 + 3=7 + 13二1 + 15 =20-15=6 + 4=5 + 15=11 + 5=10 + 1= 12-6=7 + 11 =3 + 7=7-2=6-5 =17-15 =8 + 11 =15 - 1 二2 - 1= 8-1二5 +
3、1=16 - 6= 16-1=5-2 =7 + 12 = 4-4=17-1=18 - 12 =8 + 8= 20-2 =2 + 17=10 + 8=6 + 5 =5-4=18 - 18=5 + 9二6 + 8=3 + 2二10-7=16-7=11 + 4=8 + 2=12 + 4=19-15 =4 + 16=14-7=9 + 3=5 + 4=8 + 9二17 - 12 =1 + 10=17-3 =19 - 16=16 + 2=14 + 2 =3 + 17=1 + 9=11 + 7=14-6=11 - 5 =16-13 =5 - 5二3 + 10=20 - 10二13 - 5 =4 + 3 =1
4、4-9=12 - 12=8-7=11 + 9=5 + 13 =14-8=15 + 3 =16-9=16 - 16=17-9=16 - 10=18 - 11=12-7=7-5 =5 + 3=15 + 4=4 + 2 二6-2 =9 + 1=11-4=17-8=12 - 10=19 - 10=1 + 18=19 - 5 =20-1=20-3 =4 + 1=12 + 6=19 - 13 =8-5=2 + 3二9-2 =2 + 13 =10 + 10=4 + 14=12 - 3二15-7=17-6=10 + 5 =4-1=7-7=2 + 7=13 - 13 =7 + 1= 20-7=15 - 15 =
5、6-6=17 + 1 =1 + 8=6 + 12 =18-3 =13 + 1=4 + 13 =13 - 10二1 + 5二8 + 1=8 + 6=8-3 =19 - 19=10 - 10=2 + 18=19-2 =19-8=16-15 =5 + 5 =20 - 16=7 + 4二10-9=7 + 7二11-2 =14 + 6=16-8=9 + 9 二8-8=7 - 1二3 + 12 =14 + 4=8-4=12 - 11=9 + 4=6 + 7=9 + 2 二4 + 4二16-3 =19 - 1=19-6=18-13 =16-2=20 - 18=3 + 8=3 + 13 =3 + 11 =3
6、+ 6=2 + 1 =4 + 15=2 + 16=5 + 12 =13-7=20-6=18-2 =6 + 14=12-2 =6 + 9=16 -12=17 + 2 =19 - 18=1 + 14=10-3 =17 - 13 =6 + 13二12 - 1=15 - 3 =15-9=5 - 3 =14 - 11 =15 - 12=18 - 10二1 + 2 =13 + 4 二10-5 =20-11=14 - 10=14-5 =3 + 16=15 - 6=13 - 12=13-6=1 + 17=14 + 5 =3+4=20-5=5 + 10=20-9=9 + 5=5 + 11 =18 + 1= 9-
7、7=15 + 2 二17 - 14=4 + 6=1 + 19= 11-9=12 - 8=10 + 9= 18-5=7 + 2=13 + 2 = 14-2 =8 + 10=13 + 6=2 + 9=2 + 15二 15-8=6-3 =17 - 10=3 + 14=3 + 1 二6 + 10=2 + 10= 18-9=16-4=7 + 10=5 + 8 二6 + 11 =13 + 5=13-2 =10 + 4=4 + 7=11 - 1=12 + 8=14 + 3 =18-7=19 - 17=12-4=1 + 7=17 - 11=19-7=7 + 5=14 + 1=5 + 7二17 - 17=14
8、- 14=12 + 2 =20 - 12 =4 + 11二20 - 19=9 + 10=4-3 =2-2=8 + 4 二12 + 7=6-1=19-3 =17-2 =17 + 3 =19-9=4 + 9=12 - 5二8 + 12 =2 + 4=5 + 2 二14-4=16 + 4 二10 + 2 =9 + 6=12 + 3 =1 + 3=1 - 1=4 + 5 二10 + 3 =10-4=9-9=18-6=10 + 6=19 + 1=7-6=10-2=11 - 11=16 + 1=8-6=14-12 =18 - 1= 10-8=19-4=14-13 =4 + 12 =3 + 9= 20-4=
9、15 + 1= 12-9=15 - 14= 7-3 =20 - 17=7 + 8= 10-6=11 + 6=18 - 16=4-2 =13 - 3二11 + 1=17-7=15 + 5 =11 + 2 =8 + 7=5 + 6=19 - 12 =11 + 8=12 + 1=1 + 1=18 - 15 =9 + 7=20 - 14=2 + 12 =14-1 二13 - 11=15-4=1 + 6=6-4=13 + 3二7-4=17-5 =9 + 11=9-5 =4 + 8=13 - 1=12 + 5 =18 - 14=8-2 =13 + 7=2 + 11=15-2 =1 + 11 =10 - 1
10、=18 + 2 =15 - 13 =5 - 1 =9-6=13-9=3-3 =9-8=11-7=18-8=8 + 5二3 + 15 =3-2 =14-3 =1 + 12 =7 + 3=16 - 14=20-13 =18-4=9-3 =15 - 11= 17-4=17 - 16=7 + 9= 20-8=19-11=20 - 20= 16-5=11 + 3 =7 + 13二1 + 15 =20-15 =6 + 4=5 + 15=11 + 5=10 + 1= 12-6=7 + 11 =9-4=9 + 8=2 + 6=10 + 7=5 + 14=15 - 1=2 - 1=8-1 二5 + 1 二16
11、- 6二16-1 =5-2 =7 + 12 =4-4=17 - 1=18 - 12 =8 + 8=20-2 =15 - 5 =15 - 10=16 + 3 =7 + 6=8 + 3 =5 + 9=6 + 8=3 + 2二10-7=16-7=11 + 4=8 + 2 =12 + 4=19 - 15 =4 + 16=14-7=9 + 3=5 + 4=19 - 14=13-4=1 + 13 =6 + 3 =3 + 5=16 + 2=14 + 2 =3 + 17=1 + 9=11 + 7=14-6=11 - 5 =16-13 =5 - 5二3 + 10=20 - 10=13 - 5 =4 + 3 =7
12、-2 =6-5 =17 - 15=8 + 11 =6 + 1 = 14-8=15 + 3= 16-9=16 - 16= 17-9=16 - 10= 18-11 =12-7=7-5 =5 + 3二15 + 4=4 + 2= 6-2 =10 + 8=6 + 5 =5-4=18 - 18=2 + 2=1 + 18=19-5 =20-1=20-3 =4 + 1二12 + 6=19 - 13 =8-5 =2 + 3二9-2=2 + 13 =10 + 10=4 + 14=1 + 10二17-3 =19 - 16=1 + 16二7-7=2 + 7=13 - 13 =7 + 1=20-7=15 - 15=6-
13、6=17 + 1 =1 + 8=6 + 12二18-3 =13 + 1=4 + 13=8-7=11 + 9=5 + 13 =11 - 3二19 - 19=10 - 10二2 + 18=19-2 =19-8=16 -15=5 + 5二20 - 16=7 + 4=10-9=7 + 7=11-2=14 + 6=11-4=17-8=12 - 10=19 - 10=13-8=14 + 4=8-4=12 - 11=9 + 4 二6 + 7=9 + 2 二4 + 4二16-3 =19 - 1=19-6=18-13 =16-2=20 - 18=15-7=17-6=10 + 5 =4-1二18 - 17=4 +
14、 15 =2 + 16=5 + 12 =13-7=20-6=18-2 =6 + 14=12-2 =6 + 9=16 -12=17 + 2 =19 - 18=1 + 14=1 + 5二8 + 1=8 + 6=8-3 =4 + 10=15-9=5 - 3 二14 - 11 =15 - 12=18 - 10二1 + 2=13 + 4=10-5 =20-11=14 - 10=14-5 =3 + 16=15 - 6=9 + 9二 8-8=7 - 1=3 + 12 =2 + 8= 20-5 =5 + 10= 20-9=9 + 5二5 + 11 =18 + 1 = 9-7=15 + 2=17 - 14=4
15、+ 6=1 + 19= 11-9=12 - 8=3 + 13 =3 + 11 =3 + 6=2 + 1=1 + 4=8 + 10=13 + 6=2 + 9 二2 + 15二 15-8=6-3 =17 - 10二3 + 14=3 + 1=6 + 10=2 + 10= 18-9= 16-4=17 - 13 =6 + 13 =12 - 1=15 - 3二6 + 6=10 + 4=4 + 7=11 - 1 =12 + 8=14 + 3 =18-7=19 - 17=12-4=1 + 7=17 - 11=19-7=7 + 5=14 + 1=13-6=1 + 17=14 + 5 =3 + 4=6 + 2 =
16、4 + 11 =20 - 19=9 + 10=4-3 =2-2 =8 + 4=12 + 7=6-1=19-3 =17-2 =17 + 3 =19-9=4 + 9=18-5 =7 + 2=13 + 2 =14-2 =11-6=16 + 4=10 + 2 =9 + 6=12 + 3 =1 + 3=1 - 1=4 + 5二10 + 3 =10-4=9-9=18-6=10 + 6=19 + 1=5 + 8 二6 + 11 =13 + 5=13-2 =11 - 10二 14-12 =18 - 1= 10-8=19-4=14-13 =4 + 12二3 + 9 二 20-4=15 + 1 = 12-9=15
17、 - 14=7-3 =20 - 17=17 - 17=14 - 14=12 + 2 =20-12 =3 + 3=13 - 3 二11 + 1= 17-7=15 + 5 =11 + 2 =8 + 7=5 + 6=19 -12 =11 + 8=12 + 1=1 + 1=18-15 =9 + 7=8 + 12 =2 + 4=5 + 2=14-4=3 - 1二1 + 6=6-4=13 + 3二7-4=17-5 =9 + 11二9-5 =4 + 8=13 - 1=12 + 5 =18 - 14=8-2=13 + 7=10-2=11 - 11=16 + 1 =8-6=9-1 =15 - 13 =5 - 1
18、 =9-6=13-9=3 - 3二9-8=11-7=18-8=8 + 5=3 + 15 二3-2=14-3 =1 + 12 =18 - 13 =16-2=20 - 18=3 + 8=3 + 13 =3 + 11 =3 + 6=2 + 1=1 + 4 二8 + 10=13 + 6=2 + 9 二2 + 15 =15-8=6-3 =17 - 10=3 + 14=3 + 1 =17 + 2=19 - 18=1 + 14=10-3 =17-13 =6 + 13 =12 - 1=15 - 3二6 + 6=10 + 4=4 + 7二11 - 1二12 + 8=14 + 3 =18-7=19 - 17=12
19、-4=1 + 7=14-5 =3 + 16= 15-6=13 - 12=13-6=1 + 17=14 + 5 =3+4=6 + 2 =4 + 11 =20 - 19=9 + 10=4-3 =2-2=8 + 4=12 + 7=6-1=19-3 =1 + 19=11-9=12 - 8二10 + 9=18-5=7 + 2=13 + 2 =14-2 =11 - 6二16 + 4=10 + 2 =9 + 6=12 + 3 =1 + 3=1 - 1=4 + 5二10 + 3 =10-4=10-6=11 + 6=18 - 16=4-2 =11-8=15 - 11=17-4=17 - 16=7 + 9 二20
20、-8=19-11=20 - 20=16-5=11 + 3 =7 + 13二1 + 15 =20-15 =6 + 4=2 + 12 =14-1=13 - 11 =15-4=2 + 5=9-4=9 + 8=2 + 6=10 + 7=5 + 14=15 - 1=2 - 1=8 - 1=5 + 1=16 - 6二16-1=5-2 =7 + 12 =15-2 =1 + 11 =10-1=18 + 2=2 + 14=15 - 5 =15 - 10=16 + 3 =7 + 6=8 + 3 =5 + 9二6 + 8=3 + 2=10-7=16-7=11 + 4=8 + 2=12 + 4=16 - 14=20-
21、13 =18-4=9-3 =16-11 =19 - 14=13-4=1 + 13二6 + 3 =3 + 5=16 + 2 =14 + 2 =3 + 17=1 + 9=11 + 7=14-6=11 - 5 =16-13 =11 + 5=10 + 1= 12-6=7 + 11二3 + 7=7-2 =6-5 =17-15 =8 + 11二6 + 1 =14-8=15 + 3 =16-9=16 -16=17-9=16 -10=18 - 11=12-7=17 - 1=18 - 12=8 + 8= 20-2 =2 + 17=10 + 8=6 + 5 =5-4=18 - 18=2 + 2=1 + 18=19
22、 - 5 = 20-1=20-3 =4 + 1 二12 + 6= 19-13 =8 - 5 =4 + 16=14-7=9 + 3二5 + 4二8 + 9二17 - 12 =1 + 10=17-3 =19 - 16=1 + 16=7-7=2 + 7=13 - 13 =7 + 1=20-7=15 - 15 =6-6=17 + 1=3 + 10=20 - 10=13 - 5=4 + 3=14-9=12 - 12=8-7=11 + 9=5 + 13 =11 - 3二19 - 19=10 - 10=2 + 18=19-2 =19-8=16-15 =5 + 5 二20 - 16=5 + 3 二15 + 4
23、=4 + 2=6-2 =9 + 1=11-4=17-8=12 - 10=19 - 10=13-8=14 + 4=8-4=12 - 11=9 + 4=6 + 7=9 + 2 二4 + 4二16-3 =9-2 =2 + 13 =10 + 10=4 + 14=12 - 3二15-7=17-6=10 + 5 =4-1=18 - 17=4 + 15二2 + 16=5 + 12 =13-7=20-6=18-2 =6 + 14=12-2 =6 + 12 =18-3 =13 + 1=4 + 13二13 - 10二1 + 5 =8 + 1=8 + 6=8-3 =4 + 10=15-9=5 - 3二14 - 11
24、 =15 - 12 =18 - 10=1 + 2=13+4=10-5 =10-9=7 + 7=11-2 =14 + 6=16-8=9 + 9 二8-8=7 - 1=3 + 12 =2 + 8=20-5=5 + 10=20-9=9 + 5=5 + 11=18 + 1=9-7=15 + 2=19-6=18 - 13 =16-2 =20 - 18=3 + 8=3 + 13 =3 + 11 =3 + 6=2 + 1=1 + 4=8 + 10=13 + 6=2 + 9=2 + 15二15-8=6-3 =17 - 10=3 + 14=16 -12=17 + 2 =19 - 18=1 + 14二10-3 =
25、17 - 13 =6 + 13 =12 - 1=15 - 3二6 + 6=10 + 4=4 + 7=11 - 1=12 + 8=14 + 3 =18-7=19 - 17=12-4=14-5 =3 + 16=15-6=13 - 12 =13-6=1 + 17=14 + 5 =3 + 4=6 + 2 =4 + 11 =20 - 19=9 + 10=4-3 =2-2 =8 + 4=12 + 7=6-1=1 + 19=11-9=12 - 8二10 + 9=18-5 =7 + 2 二13 + 2=14-2 =11 - 6二16 + 4=10 + 2 =9 + 6=12 + 3 =1 + 3 二1 - 1
26、=4 + 5=10 + 3 =6 + 10=2 + 10=18-9=16-4=7 + 10=5 + 8二6 + 11二13 + 5=13-2 =11 - 10二14-12 =18-1=10-8=19-4=14-13 =4 + 12 =3 + 9二20-4=17 - 11=19-7=7 + 5=14 + 1=5 + 7二17 - 17=14 - 14=12 + 2 =20 -12=3 + 3=13 - 3二11 + 1=17-7=15 + 5二11 + 2=8 + 7二5 + 6=19-12 =17-2=17 + 3 =19-9=4 + 9 二12 - 5二8 + 12 =2 + 4=5 + 2
27、=14-4=3 - 1二1 + 6=6-4=13 + 3 =7-4=17-5=9 + 11=9-5 =4 + 8=9-9=18-6=10 + 6=19 + 1=7 - 6二10-2 =11-11=16 + 1=8-6=9-1=15 - 13 =5 - 1=9-6=13-9=3-3 =9-8=11-7 =18-8=12-9=15 - 14=7-3 =20 - 17=7 + 8= 10-6=11 + 6=18 - 16=4-2=11-8=15 - 11= 17-4=17 - 16=7 + 9=20-8= 19-11=20 - 20=16-5=12 + 1=1 + 1=18 - 15 =9 + 7=
28、20 - 14=2 + 12 =14-1=13 - 11 =15-4=2 + 5=9-4=9 + 8 二2 + 6=10 + 7=5 + 14=15 - 1=2 - 1=8 - 1=12 + 5 =18 - 14=8-2=13 + 7=2 + 11=15-2 =1 + 11 =10-1=18 + 2=2 + 14=15 - 5二15 - 10二16 + 3 =7 + 6=8 + 3二5 + 9二6 + 8=3 + 2=3 + 15 =3-2=14-3 =1 + 12 =7 + 3=16 - 14=20-13 =18-4=9-3 =16-11 =19 - 14=13-4=1 + 13 =6 +
29、3 =3 + 5 二16 + 2 =14 + 2 =3 + 17=7 + 13=1 + 15 =20-15=6 + 4=5 + 15 =11 + 5 =10 + 1= 12-6=7 + 11 =3 + 7= 7-2=6-5 = 17-15 =8 + 11二6 + 1= 14-8=15 + 3 = 16-9=16 - 6=16 - 1=5-2 =7 + 12 =4-4=17 - 1=18 - 12 =8 + 8 二 20-2 =2 + 17=10 + 8=6 + 5 =5-4=18 - 18=2 + 2 =1 + 18=19 - 5 = 20-1=16-7=11 + 4=8 + 2=12 + 4
30、=19 - 15 =4 + 16=14-7=9 + 3二5 + 4二8 + 9二17 - 12 =1 + 10=17-3 =19 - 16=1 + 16 =7-7=2 + 7=13 - 13 =11 + 7=14-6=11 - 5二16-13 =5 - 5二3 + 10=20 - 10=13 - 5=4 + 3 二14-9=12 - 12=8-7=11 + 9=5 + 13 =11 - 3二19 - 19=10 - 10=2 + 18=17-9=16 - 10=18 - 11=12-7=7-5=5 + 3 =15 + 4=4 + 2 二6-2=9 + 1=11-4=17-8=12 - 10=1
31、9 - 10=13-8=14 + 4=8-4=12 - 11=4 + 1二12 + 6=19-13 =8 - 5二2 + 3二9-2 =2 + 13 =10 + 10=4 + 14=12 - 3二15-7=17-6=10 + 5 =4-1二18 -17=4 + 15二2 + 16=5 + 12 =20-7=15 - 15 =6-6=17 + 1=1 + 8=6 + 12 =18-3 =13 + 1=4 + 13二13 - 10二1 + 5=8 + 1=8 + 6=8-3 =4 + 10=15-9=5 - 3二14 - 11 =19-8=16-15 =5 + 5二20 - 16=7 + 4二10
32、-9=7 + 7=11-2 =14 + 6=16-8=9 + 9 二8 - 8=7 - 1=3 + 12 =2 + 8=20-5 =5 + 10=20-9=6 + 7 二9 + 2 =4 + 4=16-3 =19-1=19-6=18 - 13 =16-2=20 - 18=3 + 8=3 + 13 =3 + 11 =3 + 6=2 + 1=1 + 4 二8 + 10=13 + 6=2 + 9=20-6=18-2 =6 + 14=12-2 =6 + 9=16 - 12=17 + 2 =19 - 18=1 + 14=10-3 =17 - 13 =6 + 13 =12 - 1=15 - 3二6 + 6
33、=10 + 4=4 + 7=11 - 1=18 - 10=1 + 2 =13 + 4=10-5 =20-11=14 - 10=14-5 =3 + 16=15-6=13 - 12 =13-6=1 + 17=14 + 5 =3 + 4=6 + 2 =4 + 11 =20 - 19=9 + 10=5 + 11 =18 + 1=9-7=15 + 2 =17 - 14=4 + 6=1 + 19=11-9=12 - 8二10 + 9=18-5=7 + 2 =13 + 2 =14-2 =11-6=16 + 4 二10 + 2=9 + 6=15-8=14 + 3 =2-2=6-3 =18-7=8 + 4=17
34、 - 10=19 - 17=12 + 7=3 + 14=12-4=6-1=3 + 1=1 + 7=19-3 =6 + 10=17 - 11 =17-2 =2 + 10=19-7=17 + 3 =18-9=7 + 5二19-9=16-4=14 + 1=4 + 9=7 + 10=5 + 7二12 - 5二5 + 8 二17 - 17=8 + 12 =6 + 11 =14 - 14=2 + 4=13 + 5=12 + 2 =5 + 2 =13-2=20 - 12=14-4=11 -10=3 + 3二3 - 1=14-12 =13-3 =1 + 6=18 - 1=11 + 1=6-4=10-8=17-
35、7=13 + 3 =19-4=15 + 5 =7-4=1 + 3二1 - 1=4 + 5二10 + 3 =10-4=9-9=18-6=10 + 6=19 + 1=7-6=10-2 =11 - 11=16 + 1=8-6=9-1二15 - 13 =5 - 1 =9-6=13-9=2 + 10= 18-9=16-4=7 + 10=5 + 8=6 + 11 =13 + 5= 13-2=11 - 10=14-12 =18-1=10-8=19-4=14-13 =4 + 12二3 + 9 二 20-4=15 + 1 = 12-9=19-7=7 + 5 =14 + 1=5 + 7二17 - 17=14 -
36、14=12 + 2 =20-12 =3 + 3二13-3 =11 + 1=17-7=15 + 5 =11 + 2 =8+ 7二5 + 6=19 - 12 =11 + 8=17 + 3 =19-9=4 + 9=12 - 5二8 + 12 =2 + 4=5 + 2 =14-4=3 - 1=1 + 6=6-4=13 + 3 =7-4=17 - 5二9 + 11=9-5 =4 + 8=13 - 1=18-6=10 + 6=19 + 1 =7-6=10-2 =11 - 11=16 + 1=8-6=9-1二15 - 13 =5 - 1=9-6=13-9=3 - 3二9-8=11-7=18-8=8 + 5
37、=14-13 =4 + 12 =3 + 9= 20-4=15 + 1= 12-9=15 - 14=7-3 =20 - 17=7 + 8= 10-6=11 + 6=18 - 16=4-2 =11-8=15 - 11= 17-4=17 - 16=11 + 2 =8 + 7=5 + 6=19 - 12=11 + 8=12 + 1=1 + 1=18 - 15 =9 + 7=20 - 14=2 + 12 =14-1=13 - 11 =15-4=2 + 5 二9-4=9 + 8 二2 + 6=17-5 =9 + 11=9-5 =4 + 8=13 - 1=12 + 5 =18 - 14=8-2=13 + 7
38、=2 + 11=15-2 =1 + 11 =10-1=18 + 2=2 + 14=15 - 5 =15 - 10二16 + 3 =3-3 =9-8=11-7=18-8=8 + 5=3 + 15 =3-2 =14-3 =1 + 12 =7 + 3=16 - 14=20-13 =18-4=9-3 =16-11 =19 - 14=13-4=1 + 13 =20-8=19 - 11=20 - 20=16-5 =11 + 3 =7 + 13 =1 + 15 =20-15=6 + 4=5 + 15=11 + 5 =10 + 1 = 12-6=7 + 11二3 + 7 二7-2=6-5 =17-15 =5 + 14=15 - 1=2 - 1=8 - 1=5 + 1=16 - 6=16 - 1= 5-2=7 + 12 = 4-4=17-1=18 - 12=8 + 8= 20-2 =2 + 17=10 + 8=6 + 5 =5-4=8 + 3二5 + 9=6 + 8=3 + 2二10-7=16-7=11 + 4 二8 + 2=12 + 4=19-15 =4 +