In the old society, old man Zhang borrowed 1,000 yuan of Hell King's debt with rolling interest from a loan shark, with an annual interest rate of 20%, and a loan period of 2 years.
在旧社会，张老伯向一个高利贷者借了利滚利的阎王债1000元，年息20%，借期2年，到期张老伯要还高利贷者多少元．
<gadget id="calculator">1_000 + 200</gadget>
<output>1_200</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1_200 * (1/5) * 1</gadget>
<output>240</output>

<gadget id="calculator">1_200 + 240</gadget>
<output>1_440</output>

<result>1_440</result>