The product of two factors is 420. If one factor remains unchanged and the other factor is increased by 10 times, what is the product of?
两个因数的积是420，一个因数不变，另一个因数扩大10倍，则积变成多少
<gadget id="calculator">420 * 10</gadget>
<output>4_200</output>

<result>4_200</result>