Hongxing Primary School held a sports meeting. Each grade has to line up in four columns around the playground, and when they reach the rostrum, they need to slow down for teachers and principals to review until the whole team has completely passed the rostrum. There are 100 people in the sixth grade. The speed of the team walking on the playground is 60 m/min. When the team reaches the rostrum, the speed decreases to 40 m/min. After the team completely leaves the rostrum, the speed changes to 60 m/min. It is known that the distance between the front and back students is 2 meters, the circle around the playground is 400 meters, and the rostrum is 22 meters long. How much time does it take for the sixth grade team to go around the field for a week? (everyone walked 400 meters)
红星小学举行运动会．每个年级都要排成四列纵队绕操场一周，并且到达主席台的时候需要放慢速度让老师们和校长检阅直至整个队伍完全经过主席台为止．六年级一共有100人，队伍在操场上行走的速度是60米/分，当队伍到达主席台时速度降低到40米/分，队伍完全离开主席台后速度又变为60米/分．已知前后同学之间的间隔为2米，绕操场一圈为400米，主席台长22米．问六年级队伍绕场一周需要多少时间？(每个人都走了400米)
<gadget id="calculator">100 / 4</gadget>
<output>25</output>

<gadget id="calculator">25 - 1</gadget>
<output>24</output>

<gadget id="calculator">24 * 2</gadget>
<output>48</output>

<gadget id="calculator">48 + 22</gadget>
<output>70</output>

<gadget id="calculator">70 / 40</gadget>
<output>7/4 = around 1.75</output>

<gadget id="calculator">400 - 70</gadget>
<output>330</output>

<gadget id="calculator">330 / 60</gadget>
<output>11/2 = around 5.5</output>

<gadget id="calculator">(7/4) + (11/2)</gadget>
<output>29/4 = around 7.25</output>

<result>29/4 = around 7.25</result>