When a number is multiplied by 4, Xiaohua mistook the multiplication sign for the plus sign, and the result is 20. What is the correct product?
一个数乘4，小华把乘号误当成加号，得到的结果是20，正确的积应该是多少．
<gadget id="calculator">20 - 4</gadget>
<output>16</output>

<gadget id="calculator">16 * 4</gadget>
<output>64</output>

<result>64</result>