A, B, and C work together to complete a batch of parts. A completed 28% of this batch of parts, and the ratio of parts completed by B and C was 4:5. A and C produced a total of 680 parts. How many parts are there in total?
甲、乙、丙三人共同完成一批零件．甲完成这批零件的28%，乙、丙完成零件的比是4：5，甲、丙共生产了680个．求这批零件共有多少个？
<gadget id="calculator">28 / 100</gadget>
<output>7/25 = around 0.28</output>

<gadget id="calculator">1 - (7/25)</gadget>
<output>18/25 = around 0.72</output>

<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">(18/25) * (5/9)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(7/25) + (2/5)</gadget>
<output>17/25 = around 0.68</output>

<gadget id="calculator">680 / (17/25)</gadget>
<output>1_000</output>

<result>1_000</result>