(9/10) tons of cement are shipped to the construction site, (1/3) is used on the first day, and (1/4) is used on the second day, how many tons of cement are used in total?
工地运来(9/10)吨水泥，第一天用去(1/3)，第二天用去(1/4)，一共用去多少吨水泥？
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

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

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

<gadget id="calculator">(1/3) + (1/4)</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">(9/10) * (7/12)</gadget>
<output>21/40 = around 0.525</output>

<result>21/40 = around 0.525</result>