Xiao Ming's father borrows 120,000 yuan from the bank at an annual interest rate of 4.5%, and the loan period is three years. Calculated on the basis of simple interest, how much interest will Xiao Ming's father have to pay when it expires?
小明的爸爸以4.5%年利率向银行贷款12万元，借期三年，以单利计算，到期时小明的爸爸需支付的利息是多少元？
<gadget id="calculator">12 * 10_000</gadget>
<output>120_000</output>

<gadget id="calculator">4.5 / 100</gadget>
<output>0.045</output>

<gadget id="calculator">120_000 * 0.045 * 3</gadget>
<output>16_200</output>

<result>16_200</result>