The area of a rectangular orchard is 810 square meters. If its width remains the same, its length will be expanded to 5 times of its original size. How many square meters is the orchard area after expansion?
一块长方形果园的面积为810平方米，如果它的宽不变，长扩大到原的5倍．扩大后果园面积为多少平方米？
<gadget id="calculator">810 * 5</gadget>
<output>4_050</output>

<result>4_050</result>