In a square orchard of 1 hectare, each side is doubled in size, by how many hectares is the area of the orchard increased?
一个占地1公顷的正方形果园，每条边长都扩大到原来的2倍，果园的面积增加了多少公顷？
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">1 * 3</gadget>
<output>3</output>

<result>3</result>