It's a good, educational game that makes you think. It just feels very different from something like Wordle, and that's OK.
Now that I got the hang of it, I tried the easy and hard modes as well, and got them both on the first try without having to undo anything.
But as others said, I looked at the available numbers, figured out what I had to multiply to get close, what I'd have to add/subtract to get the rest of the way, and how I'd use the leftover numbers there to make the addition/subtraction possible.
Basically I brute-forced it in my head. But I think it would be enjoyable if it somehow felt more iterative, and less like I was working from the solution backwards, and then just filling the steps in all at once.