When two numbers are multiplied, one factor is multiplied by 4, and the other factor is multiplied by 5. How many times are their products?
两个数相乘，一个因数扩大4倍，另一个因数扩大5倍，它们的积多少倍．
<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<result>20</result>