A pile of coal is 15 tons. In the first month (1/3) of this pile of coal was burned, how many tons are left over?
一堆煤15吨，第一月烧了这堆煤的(1/3)，剩下的比烧了的多多少吨？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3) - (1/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">15 * (1/3)</gadget>
<output>5</output>

<result>5</result>