Intersections

Select a 3 x 3 block and a digit. If all possible cells for that digit lie in one row, the digit cannot appear anywhere else in that row outside the block. The same works for a column. Learn why this works, see pointing pairs and triples in action, and use the eliminations to find your next single.

Select a row or column and a digit. If all possible cells for that digit lie in one 3 x 3 block, the digit cannot appear elsewhere in that block outside the selected line. Learn why this works, compare Claiming with Pointing Candidates, and use the eliminations to reveal Hidden Singles.