Tom: I read a book in the library. I study math. I check out a book.
Correct: I read a book, I study math and I check out a book in the library.

Hello Tom,
Thank you for doing your homework today.
You gave teacher three sentences that can be combined into one sentence using the conjunction 'and'. Remember teacher just taught you about this a while ago.
Please take note of this and also next time try to make longer sentences.
But good job, Tom!

Teacher is looking forward to your next homework :)

Have a great day!
See you in class.

T. Melody.