The sum of the two numbers A and B is 12.1. If the decimal point of B is moved one place to the right, it is equal to A. What is A?
甲乙两数的和是12.1，乙数的小数点向右移动一位就等于甲数，甲数是多少．
<gadget id="calculator">10 + 1</gadget>
<output>11</output>

<gadget id="calculator">12.1 / 11</gadget>
<output>1.1</output>

<gadget id="calculator">12.1 - 1.1</gadget>
<output>11</output>

<result>11</result>