Maths

[Essaitch57]

All of the digits below are either a 3 or a 9.
Can you work out each digit?

7338 = ???? + ????

There are multiple ways of completing this. How many can you find?

[jim360]

Leading digits have to be 3, presumably, because it needs to be smaller than 7338. They also have to both end in 9, as 9+9 = 18 but 9+3 = 12, 3+3 = 6 wouldn't give the required 8 at the end.

So that leaves the middle digits, which I reckon can be 930+390 only. Hence there are two ways of completing the sum, but really they are just the same sum in either order.

Unless I've missed something, 3939+3399 = 7338 is the only "unique" solution.