The engineering team dug a 1,000-meter canal, dug 450 meters in the first week, and 310 meters in the second week? How many meters are left undug?
工程队挖一条1千米的水渠，第一周挖了450米，第二周挖了310米？还剩下多少米没挖？
<gadget id="calculator">1 * 1_000</gadget>
<output>1_000</output>

<gadget id="calculator">1_000 - 450 - 310</gadget>
<output>240</output>

<result>240</result>