The tractor factory produced 810 large tractors in the first three months of this year. According to this calculation, how many units can the annual output reach? (Solve using ratio method)
拖拉机厂今年前3个月生产大型拖拉机810台．照这样计算，全年产量可以达到多少台？(用比例方法解答)
<gadget id="calculator">810 / 3</gadget>
<output>270</output>

<gadget id="calculator">270 * 12</gadget>
<output>3_240</output>

<result>3_240</result>