For a canal, 40 meters were dug on the first day, and the full length (1/4) was dug on the second day. At this time, the remaining is exactly equal to the dug. How many meters is this canal?
一条水渠，第一天挖了40米，第二天挖了全长的(1/4)，这时剩下的与挖好的正好相等．这条水渠长多少米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/2) - (1/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">40 / (1/4)</gadget>
<output>160</output>

<result>160</result>