The grain and oil wholesale market has a total of 520 tons of rice, 40% of the total in the first week, and 1/4 of the total in the second week. How many tons are left? (Column comprehensive formula solution)
粮油批发市场共有520吨大米，第一周批发走总数的40%，第二周批发走总数的(1/4)．还剩多少吨？(列综合算式解答)
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">1 - (2/5) - (1/4)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">520 * (7/20)</gadget>
<output>182</output>

<result>182</result>