Harvey's started out with 25 steaks. Then he sold some, and only had 12 steaks left. He sold 4 more steaks, at 10 dollars. How many steaks did he sell in all?
Harvey sold 25-12 = 
<gadget id="calculator">25-12</gadget>
<output>13</output>
13 steaks at first.
Harvey then sold more steaks for a total of 13+4 = 
<gadget id="calculator">13+4</gadget>
<output>17</output>
17 steaks.

<result>17</result>