What is the smallest number among (2/3), (4/5), (6/7) and 0.8?
(2/3)、(4/5)、(6/7)和0.8中，最小的数是多少．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<result>2/3 = around 0.666667</result>