chuyển các số đếm sau sang dạng số thứ tự
1. three ⇒ _____________________
2. nine ⇒ _____________________
3. twenty ⇒ _____________________
4. six ⇒ _____________________
5. twelve ⇒ _____________________
6. one ⇒ _____________________
7. thirty-one ⇒ _____________________
8. seventeen ⇒ _____________________
9. two ⇒ _____________________
10. twenty-three ⇒ _____________________
11. fifteen ⇒ _____________________
12. eight ⇒ _____________________
13. five ⇒ _____________________
14. eleven ⇒ _____________________
15. twenty-four ⇒ _____________________
16. ten ⇒ _____________________
17. seven ⇒ _____________________
18. twenty-eight ⇒ _____________________
19. fifteen ⇒ _____________________
20. thirteen ⇒ _____________________