(90-81) 2 = 9 2 = 18(81-72) 4 = 9 4 = 36(72-63) 6 = 9 6 = 54(63-54) 8 = 9 8 = 72(54-45) 3 = 9 3 = 27(36-27) 7 = 9 7 = 63(27-18) 9 = 9 9 = 81(18-9) 0 = 9 0 = 0(53-46) 8 = 7 8 = 56(70-62) 5 = 8 5 = 40(23-17) 8 = 6 8 = 48(34-29) 8 = 5 8 = 40
(90-81) 2 = 9 2 = 18
(81-72) 4 = 9 4 = 36
(72-63) 6 = 9 6 = 54
(63-54) 8 = 9 8 = 72
(54-45) 3 = 9 3 = 27
(36-27) 7 = 9 7 = 63
(27-18) 9 = 9 9 = 81
(18-9) 0 = 9 0 = 0
(53-46) 8 = 7 8 = 56
(70-62) 5 = 8 5 = 40
(23-17) 8 = 6 8 = 48
(34-29) 8 = 5 8 = 40