The product of the two factors is 1600. If one factor remains unchanged and the other factor is multiplied by 4 times, the product becomes 1600.
两个因数相乘积是1600，如果一个因数不变，另一个因数扩大到原来的4倍，积就变成了多少．
<gadget id="calculator">1_600 * 4</gadget>
<output>6_400</output>

<result>6_400</result>