When two numbers are multiplied, one factor is multiplied by 5 times, the other factor is multiplied by 4, and the product is multiplied by how many times.
两个数相乘，一个因数扩大到原来的5倍，另一个因数扩大到原来的4倍，积扩大到原来的多少倍．
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<result>20</result>