Jacob is making s'mores. Each s'more takes two graham crackers and one marshmallow. If Jacob has 48 graham crackers and 6 marshmallows, how many more marshmallows does he need to buy?
First find the number of marshmallows Jacob needs: 48 graham crackers / 2 graham crackers/marshmallow = 
<gadget id="calculator">48/2</gadget>
<output>24</output>
24 marshmallows.
Then subtract the number of marshmallows Jacob already has from the number he needs to find the number he needs to buy: 24 marshmallows - 6 marshmallows = 
<gadget id="calculator">24-6</gadget>
<output>18</output>
18 marshmallows.

<result>18</result>