- 27 → 135: ×5: 27 → 135
- 135 → 15: ÷9: 135 → 15
- 15 → 65: +50: 15 → 65
- 65 → 129: +64: 65 → 129
- 129 → 206: +77: 129 → 206
Today's chain starts at 27 and has to finish on 206 in exactly 5 moves, each tile used once.
The hand: +64, +54, +77, ×5, +50, ÷9. +64 moves you up by 64; from 27 that is 91. +54 moves you up by 54; from 27 that is 81. +77 moves you up by 77; from 27 that is 104. ×5 multiplies by 5 — odd, so it keeps an odd value odd; 206 is not a multiple of 5. +50 moves you up by 50; from 27 that is 77. ÷9 only works on a multiple of 9; 27 is divisible by 9, and 206 is not.
First, ×5: 27 → 135. That leaves 71 still to gain. Then ÷9: 135 becomes 15. That leaves 191 still to gain. +50 next, taking 15 to 65. That leaves 141 still to gain. +64 next, taking 65 to 129. This is the move that crosses 100. Move 5: +77, 129 → 206. It lands exactly on 206.
Working backwards helps: the chain can finish on +50 or +77 or +64; take +77, which turns into 206 from 129. So the real question is how to reach 129 in 4 moves from 27 with the remaining tiles.
Step by step, the choices narrow: At 27, 6 tiles are legal and 2 of them still lead to 206. At 135, 5 tiles are legal and 1 of them still leads to 206. At 15, 4 tiles are legal and 3 of them still lead to 206. At 65, 3 tiles are legal and 2 of them still lead to 206. At 129, 2 tiles are legal and 1 of them still leads to 206.
Why not +54? Put it in for ×5 and the chain ends on 200, 6 below the target — a near miss, but a miss.
In total there are 30 ways to land within 10 of 206 without hitting it, and 12 orders of the right tiles that do hit it.
Tomorrow's chain uses a fresh hand; the habits — check the last digit, check what divides — carry over.