The product of two multipliers is 156. One of the multipliers is doubled while the other remains unchanged. What is the product?
两个乘数的积是156，其中一个乘数扩大2倍，另一个乘数不变，积是多少．
<gadget id="calculator">156 * 2</gadget>
<output>312</output>

<result>312</result>