Nanhe Primary School opened a rectangular wasteland last year, 15 meters long and 12 meters wide. Increase its length by 5 meters and width by 3 meters this year. How many square meters has been added this year?
南河小学去年开的一块长方形荒地，长15米，宽12米．今年把它的长增加5米，宽增加3米，今年新增加了多少平方米？
<gadget id="calculator">15 + 5</gadget>
<output>20</output>

<gadget id="calculator">12 + 3</gadget>
<output>15</output>

<gadget id="calculator">20 * 15</gadget>
<output>300</output>

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

<gadget id="calculator">300 - 180</gadget>
<output>120</output>

<result>120</result>