Dad's monthly salary is 4,500 yuan, and mother's monthly salary is 3,500 yuan. Last month's family expenses were 3/8 of their salary. How much was the balance last month?
爸爸每月的工资是4500元，妈妈每月的工资是3500元，上个月家里的开支是他俩工资的(3/8)，上个月结余多少钱？
<gadget id="calculator">4_500 + 3_500</gadget>
<output>8_000</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">1 - (3/8)</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">8_000 * (5/8)</gadget>
<output>5_000</output>

<result>5_000</result>