Place the target at 100 yds.
Take 1 shot.

Lets say that the bullet hit 2" left and 2" lower than where you wanted it to hit. Then ajust the scope 8 clicks (if the scope ajustments are 1/4" or 1/4 MOA)right and 8 clicks up.

The squares are 1" X 1"
the 1" squares allow you to know how much ajustment is needed with out going down range (if you can see the bullet hole thru your scope or spoting scope)