The length of a rectangle is 12 centimeters. If the width is reduced (1/4), how many centimeters should the length be increased, and the area remains the same.
一个长方形的长是12厘米，如果宽减少(1/4)，长要增加多少厘米，面积不变．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 / (3/4)</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">(4/3) - 1</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">12 * (1/3)</gadget>
<output>4</output>

<result>4</result>