A rectangular pillowcase is 6 decimeters long and 4 decimeters wide. If you want to sew lace around it, how many decimeters of lace do you need to buy?
一个长方形的枕套长6分米、宽4分米，现在要在四周缝上花边，至少需要买多少分米的花边？
<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<result>20</result>