Trent walked 4 blocks from his house to the bus stop. He rode the bus 7 blocks to the library. Later, he came home the same way. How many blocks did Trent travel in all?
On the way to the library, Trent went 4 blocks + 7 blocks = 
<gadget id="calculator">4+7</gadget>
<output>11</output>
11 blocks.
Trent came home the same way so he went 11 blocks + 11 blocks = 
<gadget id="calculator">11+11</gadget>
<output>22</output>
22 blocks.

<result>22</result>