Mark is looking to buy a total of 12 pieces of fruit at the store. He has already chosen 3 apples. He has also selected a bunch of bananas containing 4 bananas. How many oranges does he need to pick out to have 12 total pieces of fruit?
He has 3 apples and 4 bananas, so he has 3 + 4 = 
<gadget id="calculator">3+4</gadget>
<output>7</output>
7 pieces of fruit.
He needs to buy 12 fruit - 7 fruit = 
<gadget id="calculator">12-7</gadget>
<output>5</output>
5 oranges.

<result>5</result>