1. He is the first in our class.
2. My brother is the second son in our family.
3. Wednesday is the third day of the week.
4. Maths is our fourth lesson today.
5. Friday is the fifth day of the week.
6. This is the sixth sentence.
7. Today is my seventh birthday.
8. "H" is the eighth letter of the alphabet.
9. This book is the ninth in my bag.
10. My flat is on the tenth floor.