You are correct in your computations, Shawn is trying to make it "easier" for you. Using scope manufactorers data; 1 click = 1/4" @ 100yds, 1.25" @ 500yds and 2.50" @ 1000yds. When sighted in dead on at 100yds and the bullet drops 220" @ 1000yds, divide 220" by 2.50" = 88 clicks.
What Shawn is trying to get you to see (I think) is instead of counting each "click" look at your scopes dial and the value to/from each whole number is 4 clicks or an MOA. An MOA is roughly an inch, more precisely it's 1.047" at 100yds and 10.47" @ 1000yds. So with that in mind divide your drop (220") by what an MOA represents at 1000yds (10.47") and you more precisely get 21.012416 (21 1/4 MOA). If you reset your scopes turret back to "0" after rifle/load was zeroed at 100yds, this would have you go from "0" on your elevation turret to "21" and one more little "click".
Gets you there quicker and more precisely. I learned it the way you did, along time ago and it was hard for me to grasp the MOA version.Hope this all helps. JohnnyK.
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