There are 8 rows of apple trees, 9 in each row, and now 20 are planted, how many are there in total?
有8行苹果树，每行9棵，现在又栽了20棵，一共有多少棵．
<gadget id="calculator">8 * 9</gadget>
<output>72</output>

<gadget id="calculator">72 + 20</gadget>
<output>92</output>

<result>92</result>