Calculation is simple - 5 grandchildren = 15 crepes for one session. 40 weeks of school x 2 sessions per week x 15 = 1,200.
School holidays are still on, but grandchildren are lurking around the city, so today...
1.5 cup of flour, 1 cup of milk, 1 cup of water, 3 eggs, a pinch of salt, a spoon of oil...
FIRE!!!
Fifteen :)
PS. For more tasty crepes one can use beer instead of water.