If the perimeter of a rectangle is 6 meters and the length is 0.75 meters, what is the width in meters?
一个长方形的周长是6米，长是0.75米，那么宽是多少米．
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 - 0.75</gadget>
<output>2.25</output>

<result>2.25</result>