Six self-checking Christmas maths code-breakers for upper KS2. They mix multiplication, division, fractions of amounts, percentages, square numbers, multiplying decimals by 10 and order of operations. Each answer unlocks a letter of a Christmas joke punchline, so pupils can check their own work. Every sheet uses a different code key. Includes: cover, teacher notes, 6 pupil sheets with working space, 6 full answer keys (A4 PDF, 14 pages).