Do oral calculations 2.5*9=? what are you thinking? Write out your thought process.
做口算2.5*9=？你是怎么想的？把你的思考过程写出来．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">2.5 * 9</gadget>
<output>22.5</output>

<result>22.5</result>