A standard running track is 400 meters, so 2 laps is practically half a mile, and 4 laps is 9 meters shy of one mile. (1 mile = 1,609.344 meters)
Seven and a half laps
Three and one third.
8.5 times 20 times one half is equal to 85.
It is: 500 times 1,000 = 500,000 which is half a million
Two and a half laps!
2.5 or 2 and a half.
Two and a half laps is 1km, thus .25 of the track is 100m.
Since 1921, the IAAF has stated that a marathon's distance is standardized at 42.195K or 26 miles and 385 yards. If you are using a standard 400M track, and running exclusively in lane 1, then you will need to complete 105.4875 laps in order to complete a marathon or essentially 105 and 1/2 laps. If you use an outer lane, then you will not need to run as many laps.
20
-14
2
12.5