In a ratio, the product of two outer terms is (2/3), one inner term is (4/5), and the other inner term is what.
在一个比例中，两外项的积是(2/3)，一个内项是(4/5)，另一个内项是多少．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(2/3) / (4/5)</gadget>
<output>5/6 = around 0.833333</output>

<result>5/6 = around 0.833333</result>