共30题用时5分钟

5-3=

15+1=

15-4=

2+9=

4-3=

8+5=

9-4=

4+1=

10-6=

9-6=

6-6=

18-7=

9+6=

17-7=

8-7=

13+1=

19-8=

7-7=

19-4=

10+7=

10-8=

9-8=

8-8=

3+5=

7-4=

8+3=

2-1=

6+9=

16-12=

13-12=