Chap 2+18+3=23

1 Chap 1 :giới thiệu 

2 Chap 2 

3 Chap 3 

4 Chap four :)) 

5 Chap fai:)) 

6 Chap sáu=)) 

7 Chap bảy 

8 Chap 4+4=8 

9 Chap 3×3=9 

10 Chap 20-10=10 

11 Chap mười 1 

12 Chap 24:2=12=)) 

13 Chap 10 ba:) 

14 Chap fourteen :))) 

15 Chap mười lăm 

16 Chap 10 six 

17 Chap 1 mười 7 

18 Chap 18 

19 Chap 10+9=19 

20 Chap 2 mươi 

21 Chap 21 

22 Chap hai hai 

23 Chap 2+18+3=23 

24 Chap 6×4=24 

25 Chap 2 mươi lăm 

26 Chap 4×6+2=26 

27 Chap 27 

28 Chap 20+tám=28 

29 Chap hai 9 

30 Chap 3×10=30 