Teams A and B work together to overhaul a highway and take 7 days to complete the overhaul. Team A has overhauled 840 meters, and team B has overhauled 1050 meters. How much less is team A than team B in overhauling per day?
甲、乙两队一起检修一条公路，共用7天检修完．甲队检修了840米，乙队检修了1050米，甲队比乙队平均每天少检修多少米？
<gadget id="calculator">1_050 / 7</gadget>
<output>150</output>

<gadget id="calculator">840 / 7</gadget>
<output>120</output>

<gadget id="calculator">150 - 120</gadget>
<output>30</output>

<result>30</result>