Well where I come from to make a 11 number call bet would be three call bets overlapping. That is because a call bet is actually the number you call and 2 numbers each side. So that gives you 5 numbers. So rather call two call bets and place a 10 number bet. I only call two numbers but make sure to overlap. So usually I cover +/- 7 numbers some with 2 chips on if you get my drift.
Cheers
Toxic