Donate four times to Hope Primary School, the first donation amount is 40 yuan more than the annual total (1/5), the second donation amount is 100 yuan less than the remaining amount (1/2), and the third donation amount 20 yuan more than the remaining amount (3/4), donate all the remaining 380 yuan for the fourth time. How much did he donate in total?
四次捐款给希望小学，第一次捐助额比全年总额的(1/5)多40元，第二次捐助额比剩下金额的(1/2)少100元，第三次捐助额比剩下金额的(3/4)多20元，第四次把剩下的380元全部捐出．问他一共捐了多少钱？
<gadget id="calculator">380 + 20</gadget>
<output>400</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">400 / (1/4)</gadget>
<output>1_600</output>

<gadget id="calculator">1_600 - 100</gadget>
<output>1_500</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1_500 / (1/2)</gadget>
<output>3_000</output>

<gadget id="calculator">3_000 + 40</gadget>
<output>3_040</output>

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

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">3_040 / (4/5)</gadget>
<output>3_800</output>

<result>3_800</result>