There are 18 rows of pear trees with 16 trees in each row and 15 rows of apple trees with 12 trees in each row. How many more pear trees are there than apple trees?
果园里有18行梨树，每行16棵，15行苹果树，每行12棵，梨树比苹果树多多少棵？
<gadget id="calculator">16 * 18</gadget>
<output>288</output>

<gadget id="calculator">12 * 15</gadget>
<output>180</output>

<gadget id="calculator">288 - 180</gadget>
<output>108</output>

<result>108</result>