Xiao Ming goes to a sporting goods store to buy table tennis balls. The difference is 8.9 yuan if he buys 10, and 1.6 yuan left after buying 5. How much money does Xiao Ming have?
小明去体育用品专卖店买乒乓球，买10个还差8.9元，买5个还剩1.6元，小明有多少钱？
<gadget id="calculator">8.9 + 1.6</gadget>
<output>10.5</output>

<gadget id="calculator">10 - 5</gadget>
<output>5</output>

<gadget id="calculator">10.5 / 5</gadget>
<output>2.1</output>

<gadget id="calculator">2.1 * 10</gadget>
<output>21</output>

<gadget id="calculator">21 - 8.9</gadget>
<output>12.1</output>

<result>12.1</result>