Anna is trying to buy books for her local library. She had a budget of $16, and she has already spent $4. She also bought 2 books today, and both books cost her the same amount of money. If Anna has $2 left in her budget, how much did each of the books cost?
Anna had already spent some money, so she started the day with $16 - $4 = $
<gadget id="calculator">16-4</gadget>
<output>12</output>
12.
She has money left in the budget, so she spent a total of $12 - $2 = $
<gadget id="calculator">12-2</gadget>
<output>10</output>
10 on the books.
Therefore each book cost her $10 / 2 = $
<gadget id="calculator">10/2</gadget>
<output>5</output>
5.

<result>5</result>