There used to be (8/9) tons of coal in the school cafeteria, and after (1/4) was used up, (1/4) ton of coal was bought, so is the coal in the cafeteria more or less than before? More (less) how many tons of coal? (Calculation instructions)
学校食堂原来有(8/9)吨的煤，用去(1/4)后，又买来(1/4)吨煤，那么现在食堂的煤比原来多还是少？多(少)多少吨煤？(计算说明)
<gadget id="calculator">8 / 9</gadget>
<output>8/9 = around 0.888889</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(8/9) - (2/3)</gadget>
<output>2/9 = around 0.222222</output>

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

<gadget id="calculator">(2/9) + (1/4)</gadget>
<output>17/36 = around 0.472222</output>

<gadget id="calculator">(8/9) - (17/36)</gadget>
<output>5/12 = around 0.416667</output>

<result>5/12 = around 0.416667</result>