A certain number is multiplied by 10, divided by 13, and the resulting quotient is added to a certain number. Add 80, the sum is 1000, find a certain number.
某数乘以10，除以13，所得商加某数．再加80，和是1000，求某数．
<gadget id="calculator">1_000 - 80</gadget>
<output>920</output>

<gadget id="calculator">10 / 13</gadget>
<output>10/13 = around 0.769231</output>

<gadget id="calculator">(10/13) + 1</gadget>
<output>23/13 = around 1.769231</output>

<gadget id="calculator">920 / (23/13)</gadget>
<output>520</output>

<result>520</result>