8
3
9
2
7
4
5
2
1
5
2
1
7
9
1
2
9
5
8
3
2
1
7
3
1
6
9
4
8
4
9
5
1
5
4
6
2
There are 6,670,903,752,021,072,936,960 valid completed Sudoku grids — that's 6.7 sextillion.
There are 6,670,903,752,021,072,936,960 valid completed Sudoku grids — that's 6.7 sextillion.
Studies suggest regular puzzle solving may help maintain cognitive function and build cognitive reserve as we age.
Studies suggest regular puzzle solving may help maintain cognitive function and build cognitive reserve as we age.