There are 36 white rabbits, 20% less than gray rabbits. How many gray rabbits are there?
白兔有36只，比灰兔少20%．灰兔有多少只？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">36 / (4/5)</gadget>
<output>45</output>

<result>45</result>