Kobayashi reads a story book and reads (2/3) of the whole book in 4 days. At this rate, how many days will it take for him to finish the book? (Solution of column equation)
小林看一本故事书，4天看了全书的(2/3)，照这样的速度，他看完这本书还需多少天？(列方程解)
<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) / 4</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/3) / (1/6)</gadget>
<output>2</output>

<result>2</result>