There is a series of numbers: 1, 4, 9, 16, 25, ..., how much is the tenth number greater than the ninth number?
有一列数：1，4，9，16，25，…，第十个数比第九个数大多少？
<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">9 ** 2</gadget>
<output>81</output>

<gadget id="calculator">100 - 81</gadget>
<output>19</output>

<result>19</result>