Yumiao Primary School showed love in the earthquake resistance. The first and second grades donated 160 yuan, the third and fourth grades donated twice as much as the first and second grades, and the fifth and sixth grades donated 80 yuan less than the sum of the previous four grades. How much is the donation for the fifth and sixth grades?
育苗小学抗地震献爱心．一、二年级捐款160元，三、四年级捐款数是一、二年级的2倍，五、六年级捐款数比前四个年级捐款数的和少80元．五、六年级捐款多少元？
<gadget id="calculator">160 * 2</gadget>
<output>320</output>

<gadget id="calculator">320 - 80</gadget>
<output>240</output>

<gadget id="calculator">160 + 240</gadget>
<output>400</output>

<result>400</result>