length of (7/8) meters of rope, after using up part of the remaining (4/5), how many meters are left.
一根长(7/8)米的绳子，用去一部分后还剩(4/5)，还剩多少米．
<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(7/8) * (4/5)</gadget>
<output>7/10 = around 0.7</output>

<result>7/10 = around 0.7</result>