The number A is 60, the number B is 20% less than the number A, what is the number B?
甲数是60，乙数比甲数少20%，乙数是多少．
<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">60 * (4/5)</gadget>
<output>48</output>

<result>48</result>