First find the total number of minutes Gretchen spends sitting at her desk: 6 hours * 60 minutes/hour = <<6*60=360>>360 minutes

Then divide this amount by 90 minutes to find how many walking breaks Gretchen takes: 360 minutes / 90 minutes/break = <<360/90=4>>4 breaks

Then multiply the number of breaks by the length of each break to find how long Gretchen spends walking: 4 breaks * 10 minutes/break = <<4*10=40>>40 minutes

# Answer

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<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Gretchen read that you should spend 10 minutes walking for every 90 minutes you spend sitting. If Gretchen spends 6 hours working at her desk, how long will she spend walking?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
40
Gretchen read that you should spend 10 minutes walking for every 90 minutes you spend sitting. If Gretchen spends 6 hours working at her desk, how long will she spend walking?
train