Xiaofang bought 9 table tennis balls at 0.85 yuan each, and she took 9 yuan with her. How much do you want to get back?
小芳买了9个乒乓球，每个0.85元，她带去9元，要找回多少钱？
<gadget id="calculator">0.85 * 9</gadget>
<output>7.65</output>

<gadget id="calculator">9 - 7.65</gadget>
<output>1.35</output>

<result>1.35</result>