Xiao Ming deposits the New Year's money 600 yuan given by his father in the bank as a lump sum deposit for 2 years, with an annual interest rate of 3.50%. After the maturity date, what is the total amount of principal and interest?
小明将爸爸给的压岁钱600元存入银行整存整取2年，年利率3.50%，到期时后，本金和利息共多少元．
<gadget id="calculator">3.5 / 100</gadget>
<output>0.035</output>

<gadget id="calculator">600 * 0.035 * 2</gadget>
<output>42</output>

<gadget id="calculator">600 + 42</gadget>
<output>642</output>

<result>642</result>