Adding two 0s at the end of a number will increase the number by 1980 from the original number. What is the number?
在一个数的后面补上两个0，得到的数比原来的数增加了1980，这个数是多少．
<gadget id="calculator">100 - 1</gadget>
<output>99</output>

<gadget id="calculator">1_980 / 99</gadget>
<output>20</output>

<result>20</result>