Erica sees 9 butterflies in the garden.  She sees one-third of them fly away.  How many butterflies are left in the garden?
Erica sees 9 / 3 = 
<gadget id="calculator">9/3</gadget>
<output>3</output>
3 butterflies fly away.
There are 9 - 3 = 
<gadget id="calculator">9-3</gadget>
<output>6</output>
6 butterflies still left in the garden.

<result>6</result>