To make a set of clothes, use X meters of cloth for the trousers, and (8/5) for the jacket to use for the trousers. How much more cloth is used for the jacket than the trousers?
做一套衣服，裤子用布X米，上衣用布是裤子的(8/5)，上衣比裤子多用布多少米．
<gadget id="calculator">8 / 5</gadget>
<output>8/5 = around 1.6</output>

<gadget id="calculator">(8/5) - 1</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>