1. كتابين 2. اتنين كتاب 3. اتنين كتب 4. كتابين اتنين بس ده عامية بس

One book=كتاب Two books= كتابان/كتابين Three books=ثلاث كتب Four books=اربع كتب Five books=خمس كتب There are rules for using numbers in Arabic. When counting one and two, we don't mention the number, we mention the noun only. As abu basil said, we say كتابين اثنين when confirming. I'm not good at explaining, hope someone can explain better.

كتابين by itself implies the meaning of doubleness , no need to add "ithnani" but if you were confirming you can say كتابين اثنين

Mona labeeb, I will search more about the male-female book-number later :)

7asan8mog, Mona labeeb, shokran!