the distance around a track is 400m. if you take 14 laps around the track what is the total distance you walk? use mental math

Well, if you go around the track once, that's 400m. Going around the track once is one lap. So, if you went around 14 times, that would be going 400m each time. In your head, you would find the product of 14 and 400, which would be 5600m. Your total distance would be 5600m.

to do it in mental math: you can ignore the zeroes in 400 for now.

4*14 = 4*10 + 4*4 = 40 + 16 = 56

now add the zeroes back on: 5600m