The school transported (2/3) tons of coal, used (1/4) tons, and used the remaining (2/3), how many tons were used?
学校运来(2/3)吨煤，用去(1/4)吨，又用去余下的(2/3)，又用去多少吨？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(2/3) - (1/4)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">(5/12) * (2/3)</gadget>
<output>5/18 = around 0.277778</output>

<result>5/18 = around 0.277778</result>