The students donated money to the disaster area. The first donation was 4,000 yuan, and the second donation was 4,500 yuan. How much did the amount increase?
同学们向灾区捐款，第一次捐款4000元，第二次捐款4500元，捐款数额上升了百分之几？
<gadget id="calculator">4_500 - 4_000</gadget>
<output>500</output>

<gadget id="calculator">500 / 4_000</gadget>
<output>1/8 = around 0.125</output>

<result>1/8 = around 0.125</result>