Workers lay a roadbed. If they pave 260 meters per day, the road length will be extended by 8 days;
工人铺一条路基，若每天铺260米，铺完全路长就得延长8天；若每天铺300米，铺完全路长仍要延长4天，这条路长多少米．
<gadget id="calculator">260 * 8</gadget>
<output>2_080</output>

<gadget id="calculator">300 * 4</gadget>
<output>1_200</output>

<gadget id="calculator">2_080 - 1_200</gadget>
<output>880</output>

<gadget id="calculator">300 - 260</gadget>
<output>40</output>

<gadget id="calculator">880 / 40</gadget>
<output>22</output>

<gadget id="calculator">22 + 8</gadget>
<output>30</output>

<gadget id="calculator">260 * 30</gadget>
<output>7_800</output>

<result>7_800</result>