A rectangular tablecloth, 8 decimeters long, 1 decimeter shorter than the width, with lace sewn around it, how many meters of lace is needed?
一块长方形桌布，长8分米，宽比长短1分米，四周缝上花边，需要花边多少米？
<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<gadget id="calculator">30 / 10</gadget>
<output>3</output>

<result>3</result>