5.12 Wenchuan Earthquake, a certain school actively donated to the disaster area. The sixth grade donated 18,000 yuan, and the sixth grade donated 4,000 yuan less than the fifth grade. How much is the fifth grade donation?
5.12汶川大地震，某校积极向灾区捐款，六年级捐款18000元，六年级捐款数比五年级的2倍少4000，五年级捐款多少元？
<gadget id="calculator">18_000 + 4_000</gadget>
<output>22_000</output>

<gadget id="calculator">22_000 / 2</gadget>
<output>11_000</output>

<result>11_000</result>