I suspect that the poster on maths at Christmas (Teacher magazine, TES, November 25) was produced by a maths specialist. May I suggest that next year you run the material past an RE teacher?
I am afraid that Advent is not "the time between All Saints Day on November 30 and Christmas Day". All Saints Day is November 1 and, contrary to the belief of Advent calendar manufacturers, Advent starts four Sundays before Christmas. For penance, as an added mathematical exercise, you can investigate whether that is always the first Sunday in December.
Head of RE
St Richard Gwyn RC high school Barry, Vale of Glamorgan