If the base of a parallelogram increases (1/10) and the height decreases (1/10), what is the area?
一个平行四边形的底增加(1/10)，高减少(1/10)，则面积多少．
<gadget id="calculator">99 / 100</gadget>
<output>99/100 = around 0.99</output>

<gadget id="calculator">1 - (99/100)</gadget>
<output>1/100 = around 0.01</output>

<result>1/100 = around 0.01</result>