There are 27 white rabbits, and the number of gray rabbits is 4 times that of white rabbits. How many fewer white rabbits are there than gray rabbits?
白兔子有27只，灰兔子的只数是白兔子的4倍，白兔子比灰兔子少多少只？
<gadget id="calculator">27 * 4</gadget>
<output>108</output>

<gadget id="calculator">108 - 27</gadget>
<output>81</output>

<result>81</result>