The sum of the two numbers A and B is 42.13. If the decimal point of A is moved to the left by one bit, it is exactly equal to the number B. What is the number A?
甲、乙两数的和是42.13，甲数的小数点向左移动一位就恰好等于乙数，则甲数是多少．
<gadget id="calculator">10 + 1</gadget>
<output>11</output>

<gadget id="calculator">42.13 / 11</gadget>
<output>3.83</output>

<gadget id="calculator">3.83 * 10</gadget>
<output>38.3</output>

<result>38.3</result>