road of 100 meters is built, 30% of the total length is repaired on the first day, and 27.5% of the total length is repaired on the second day, how many meters are left?
修一段100米的公路，第一天修了全长的30%，第二天修了全长的27.5%，还剩多少米．
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">27.5 / 100</gadget>
<output>0.275</output>

<gadget id="calculator">1 - (3/10) - 0.275</gadget>
<output>0.425</output>

<gadget id="calculator">100 * 0.425</gadget>
<output>42.5</output>

<result>42.5</result>