The average of the eight numbers is 78. After removing one number, the average of the remaining numbers is 74.5. What is the removed number?
八个数的平均数是78，去掉一个数后，余下的数的平均数是74.5，去掉的数是多少？
<gadget id="calculator">78 * 8</gadget>
<output>624</output>

<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">74.5 * 7</gadget>
<output>521.5</output>

<gadget id="calculator">624 - 521.5</gadget>
<output>102.5</output>

<result>102.5</result>