[wes1350]

I'd prefer the rows, columns and diagonals to have their current sums visible next to the desired totals. Right now, it's tedious to have to add all the numbers up for each one.

[prawn]

Tried a couple and didn't mind the concept, but agree that summing things gets tedious enough that I wouldn't continue, return or recommend it.

If the interface doesn't present an obvious way to add the current totals, it could be colour-coded in a way that experienced players possibly learn how far off they are. Use cool colours for under, and warm colours for over?

[voisin]

This, 100%. I enjoyed it but as soon as I moved up to more challenging levels and found myself just repeating addition I got frustrated by the tedium.

[koiueo]

To me that was the point of the puzzle.

Your suggestion would kill the challenge, turning the game into a casual dopamine inducer.

[madmonk]

Good suggestion!