The school used to have a test field with a length of 10.8 meters and a width of 6.4 meters. Later, the school was expanded to increase the length by 2.1 meters. How many square meters is the test field of the school now?
学校原来有一块长10.8米，宽6.4米的试验田，后来学校扩建，使长增加了2.1米，现在学校的实验田有多少平方米？
<gadget id="calculator">10.8 + 2.1</gadget>
<output>12.9</output>

<gadget id="calculator">12.9 * 6.4</gadget>
<output>82.56</output>

<result>82.56</result>