The construction team used 200 tons of cement to build a building, which was 50 tons less than planned. What percent of the cement was actually used?
建筑队建一栋楼用去水泥200吨，比计划少用50吨，实际用的水泥是计划的百分之几？
<gadget id="calculator">200 + 50</gadget>
<output>250</output>

<gadget id="calculator">200 / 250</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>