The number B is obtained by reducing the number A by 10 times. It is known that the difference between the numbers A and B is 20.7. What is the number A?
把甲数缩小10倍后得到乙数，已知甲、乙两数之差是20.7，甲数是多少．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">20.7 / 9</gadget>
<output>2.3</output>

<gadget id="calculator">2.3 * 10</gadget>
<output>23</output>

<result>23</result>