If the product of two numbers is 100, one of the numbers doubles and the other remains the same. How much does the product increase?
两个数相乘积是100，其中一个数扩大2倍，另一个数不变，积增加多少．
<gadget id="calculator">100 * 2</gadget>
<output>200</output>

<gadget id="calculator">200 - 100</gadget>
<output>100</output>

<result>100</result>