- 52 → 312: ×6: 52 → 312
- 312 → 321: +9: 312 → 321
- 321 → 261: −60: 321 → 261
- 261 → 29: ÷9: 261 → 29
- 29 → 106: +77: 29 → 106
From 52 to 106: 5 moves, no tile twice, and only one set of tiles gets there.
The hand: ÷4, −60, ÷9, +77, +9, ×6. ÷4 only works on a multiple of 4; 52 is divisible by 4, and 106 is not. −60 takes 60 off; from 52 that is -8, which is below zero, so not yet. ÷9 only works on a multiple of 9; 52 is not divisible by 9, and 106 is not. +77 moves you up by 77; from 52 that is 129. +9 moves you up by 9; from 52 that is 61. ×6 multiplies by 6 — an even number, so it can never land on an odd target directly; 106 is not a multiple of 6.
Working backwards helps: the final move must be +77, because 29 is the only value in reach that turns into 106. So the real question is how to reach 29 in 4 moves from 52 with the remaining tiles.
First, ×6: 52 → 312. This is the move that crosses 100. Then +9: 312 becomes 321. That is 215 above the target, to be brought down. Then −60: 321 becomes 261. That is 155 above the target, to be brought down. ÷9 next, taking 261 to 29. That leaves 77 still to gain. Move 5: +77, 29 → 106. It lands exactly on 106.
Step by step, the choices narrow: At 52, 4 tiles are legal and 1 of them still leads to 106. At 312, 4 tiles are legal and 2 of them still lead to 106. At 321, 2 tiles are legal and 1 of them still leads to 106. At 261, 2 tiles are legal and 1 of them still leads to 106. At 29, 1 tile is legal and 1 of them still leads to 106.
Why not ÷4? Play ÷4, +77, ÷9, +9, ×6 and the chain ends on 114, 8 above the target — a near miss, but a miss.
In total there are 16 ways to land within 10 of 106 without hitting it, and 2 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.