Marcus had 18 pebbles. He skipped half of them across the lake, but Freddy gave him another 30 pebbles. How many pebbles does Marcus have now?
Marcus had 18/2 = 
<gadget id="calculator">18/2</gadget>
<output>9</output>
9 pebbles left.
After Freddy gave him more, he has 9 + 30 = 
<gadget id="calculator">9+30</gadget>
<output>39</output>
39 pebbles.

<result>39</result>