It has been 4 days to build a canal with a length of 11.1 kilometers, 0.85 kilometers per day, and the rest will be completed in 7 days. How many miles per day on average?
修一条长11.1千米的水渠，已经修了4天，每天修0.85千米，剩下的要7天修完．平均每天修多少千米？
<gadget id="calculator">4 * 0.85</gadget>
<output>3.4</output>

<gadget id="calculator">11.1 - 3.4</gadget>
<output>7.7</output>

<gadget id="calculator">7.7 / 7</gadget>
<output>1.1</output>

<result>1.1</result>