There are 2000 cartons of milk in the store, (1/2) of the total is sold in the morning, and (2/5) of the total is sold in the afternoon, how many cartons are left?
商店有2000箱牛奶，上午卖出总数的(1/2)，下午卖出总数的(2/5)，还剩多少箱？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (1/2) - (2/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">2_000 * (1/10)</gadget>
<output>200</output>

<result>200</result>