There are (4/5) tons of coal in a pile, (1/10) of the total is used the first time, and (1/10) tons is used the next day, how many tons are used in two times?
一堆煤有(4/5)吨，第一次用去总数的(1/10)，第二天用去(1/10)吨，两次一共用去多少吨？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(4/5) * (1/10)</gadget>
<output>2/25 = around 0.08</output>

<gadget id="calculator">(2/25) + (1/10)</gadget>
<output>9/50 = around 0.18</output>

<result>9/50 = around 0.18</result>