The price of a commodity increases by 10% in November compared to October, and in December increases by 5% compared to November. Compared with October, how much is the total price increase of this commodity?
一种商品，11月比10月涨价10%，12月又比11月涨价5%，与10月相比，这种商品一共涨价多少？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 + (1/10)</gadget>
<output>11/10 = around 1.1</output>

<gadget id="calculator">(11/10) * (11/10)</gadget>
<output>121/100 = around 1.21</output>

<gadget id="calculator">(121/100) - 1</gadget>
<output>21/100 = around 0.21</output>

<result>21/100 = around 0.21</result>