Column calculation: 20% of a number is 90 (2/3), what is this number?
列式计算：一个数的20%是90的(2/3)，这个数是多少？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(2/3) / (1/5)</gadget>
<output>10/3 = around 3.333333</output>

<gadget id="calculator">90 * (10/3)</gadget>
<output>300</output>

<result>300</result>