Comment by coffeeaddict1

o3-mini-high solves this correctly:

```

We can “stick‐to the order” of the digits and allow concatenation. For example, one acceptable answer is

  40:  1 – 2 × 3 + 45    because 1 – (2×3) + 45 = 1 – 6 + 45 = 40

and another is

  80:  12 ÷ 3 × 4 × 5    because 12÷3 = 4, then 4×4×5 = 16×5 = 80

In both cases the digits 1,2,3,4,5 appear in order without rearrangement.

```

However, it took 8 minutes to produce that.