There are 18 rows of pear trees planted in the garden, with 30 trees in each row. There are 15 rows of apple trees, each with 22 trees. How many fruit trees are there in the orchard? (column synthesis)
园里种梨树18行，每行30棵．苹果树15行，每行22棵．果园里共有果树多少棵？(列综合式)
<gadget id="calculator">30 * 18</gadget>
<output>540</output>

<gadget id="calculator">22 * 15</gadget>
<output>330</output>

<gadget id="calculator">540 + 330</gadget>
<output>870</output>

<result>870</result>