Sum Puzzle· Advanced

Goal

Fill in blank cells with numbers 1-9 so each group sums to its clue

How to Play

  • Tap a blank cell to select it
  • Enter a number using the keypad below
  • Toggle memo mode to jot down candidate numbers

Sum Rule

The numbers in each group must add up to the clue shown in the black cell.

6↓123OK
6↓124NG

No-Repeat Rule

You cannot use the same number twice within the same sum group.

123OK✓
122NG✗

Completed Example

  • Place numbers 1 through 9 in the white cells
  • No number may repeat within the same sum group
  • The numbers in each group must add up to the clue shown in the black cell
15↓4↓7→6112→93

Tip

  • Start with groups that have the fewest possible combinations
  • For two-cell groups, a sum of 3 means 1+2, and a sum of 17 means 8+9
  • Use memo mode to note candidate numbers and reduce mistakes

Adults who regularly solve number puzzles show significant improvements in arithmetic reasoning, working memory, and attention. Neuroimaging studies also confirm that constraint satisfaction tasks activate prefrontal executive functions.

  • Number puzzles and 14 cognitive measures in adults 50+ (Int J Geriatr Psychiatry, 2019)
  • Constraint satisfaction tasks activate prefrontal executive functions (Neuropsychologia, 2018)