A rectangular wall is 10 meters long and 2 meters 5 decimeters high. If you want to paste wallpaper on the wall, how many square meters of wallpaper is needed?
一堵长方形的墙，长10米，高2米5分米，要在墙面上贴上墙纸，需要墙纸多少平方米．
<gadget id="calculator">10 * 2.5</gadget>
<output>25</output>

<result>25</result>