A school used 150 tons of water in April, saving 30 tons compared with March. The water used in April is a fraction of that in March.
一学校四月份用水150吨，比三月份节约了30吨，四月份用水是三月份的几分之几多少．
<gadget id="calculator">150 + 30</gadget>
<output>180</output>

<gadget id="calculator">150 / 180</gadget>
<output>5/6 = around 0.833333</output>

<result>5/6 = around 0.833333</result>