Xiaoxi's father deposits 20,000 yuan in the bank for three years and the annual interest rate is calculated at 3.50%. How much can he get back the principal and interest when it matures?
小西的爸爸把2万元存人银行，整存整取三年，年利率按3.50%计算，到期时，他可取回本金和利息共多少？
<gadget id="calculator">2 * 10_000</gadget>
<output>20_000</output>

<gadget id="calculator">3.5 / 100</gadget>
<output>0.035</output>

<gadget id="calculator">20_000 * 0.035 * 3</gadget>
<output>2_100</output>

<gadget id="calculator">20_000 + 2_100</gadget>
<output>22_100</output>

<result>22_100</result>