To build a canal with a length of 720 meters, the full length (2/3) was built in the first 8 days. According to this calculation, how many days will it take to finish the rest? (Answer with different knowledge points, at least three)
修一条长720米的水渠，前8天修了全长的(2/3)，照这样计算，余下的还要多少天修完？(用不同的知识点解答，至少三种)
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(2/3) / 8</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">720 * (1/12)</gadget>
<output>60</output>

<gadget id="calculator">(1/3) / 60</gadget>
<output>1/180 = around 0.005556</output>

<gadget id="calculator">720 * (1/180)</gadget>
<output>4</output>

<result>4</result>