Last year on Arbor Day, the third graders planted 14 rows of trees in the morning and 13 rows in the afternoon, with an average of 28 trees per row. How many trees did the third graders plant in total?
去年植树节三年级同学上午种树14行，下午种树13行，平均每行种28棵树，三年级同学一共种树多少棵？
<gadget id="calculator">14 + 13</gadget>
<output>27</output>

<gadget id="calculator">27 * 28</gadget>
<output>756</output>

<result>756</result>