At the mall, Leona bought a T-shirt and a book for a total of $28. The book cost $12. How much did the T-shirt cost?
What is the unknown information?
Let x represent the unknown information. Write an addition equation that models the problem
Solve the equation by writing a related equation and showing the answer
Answer the question in a complete sentence
so, what is unknown?
You can't solve a problem without knowing what you are looking for.