Patrice found a book that was 2 1/4 inches thick. She stacked it with another book with the same thickness. How tall was the stack?

Answer:
The stack is 4½ inches tall.
Step-by-step explanation:
If both books are the same thickness, you are adding 2¼ + 2¼. This means that it will be 4 and two quarters. 2/4 is the same as 1/2, so simplifying gives you 4½.