The four classes in the first grade of junior high school donated money to the Hope Project. The first class donated 2/7 of the total, the second class donated 600 yuan, the third class was half of the sum of the first and second classes, and the fourth class donated 500 yuan , How much did the four classes donate in total?
实外初一年级四个班为希望工程捐款，一班捐了总数的(2/7)，二班捐了600元，三班是一班、二班总和的一半，四班捐了500元，问四个班共捐了多少元？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">600 * (1/2)</gadget>
<output>300</output>

<gadget id="calculator">300 + 600 + 500</gadget>
<output>1_400</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(2/7) * (1/2)</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 - (2/7) - (1/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">1_400 / (4/7)</gadget>
<output>2_450</output>

<result>2_450</result>