factory planned to burn 120 tons of coal in May, but actually only used 70% of the original plan. How many tons of coal was saved in May?
某工厂五月份计划烧煤120吨，实际只用了原计划的70%，五月份节约用煤多少吨？
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 - (7/10)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">120 * (3/10)</gadget>
<output>36</output>

<result>36</result>