40% of the total length of a canal has been dug in a certain village, and there are still 120 meters left to be dug. How many meters have been dug for this canal? (answer in 5 ways)
某村挖一条水渠，已经挖完了全长的40%，还剩下120米没挖，这条水渠已经挖了多少米？(用5种方法解答)
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">120 / (3/5)</gadget>
<output>200</output>

<gadget id="calculator">200 * (2/5)</gadget>
<output>80</output>

<result>80</result>