The area of a trapezoid is 22 square meters, the lower base is 6 meters, and the height is 4 meters. What is its upper base?
一块梯形地的面积是22平方米，下底是6米，高是4是米，它的上底是多少．
<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">22 * (1/2)</gadget>
<output>11</output>

<gadget id="calculator">11 - 6</gadget>
<output>5</output>

<result>5</result>