Amplify the difference of a number minus 7 to 100 times the original, add 200, and then multiply the sum by 10 times, which is exactly 10000. What is this number?
把一个数减去7的差扩大到原来的100倍，再加上200，然后把和扩大都原来的10倍，正好是10000，这个数是多少？
<gadget id="calculator">1_000 - 200</gadget>
<output>800</output>

<gadget id="calculator">800 / 100</gadget>
<output>8</output>

<gadget id="calculator">8 + 7</gadget>
<output>15</output>

<result>15</result>