Activity: Cross-Arithmetic Puzzle Directions: Find the missing terms of each sequence. The common difference (d) serves as your clue in completing the cross-arithmetic puzzle. One - across is done as an example. Across Down 1. d = 4 2. d = -4 3. d=-12 4. d = 19 5. d = -12 6.d = 0.5 7.d = -7 8. d = 2 1. d = 12 4.d = 1/2 9. d = 4 10. d= -4 11.d = -4 12.d ='-19 13. d= -1.5 9 10 8 11 4 8 12 16 1 20 28 9 8 16 2 24 16 18 12 40 24 20 3 7 40 16 1 4 29 13 32 17 4 6 38 57 76 -2.5 -3 1/2 -5 5 1 24 -12 -6.5​