Addition Digit Double Printable Games Search: Double Digit Addition Games Printable. The Letter-to-Number Cipher (or Number-to-Letter Cipher) consists in replacing each letter by its position in the alphabet, for example A=1, B=2, Z=26, hence its over name A1Z26 Level 1: single digit Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models Use a set of game dominoes or print a set above ...