The case notes
When every black dot is shown
All markers named in this lesson are shown. Watch a worked example, then try the idea in a puzzle.
Put it into practice
All black dots are marked
A black Kropki dot joins digits where one is double the other. This puzzle says every black dot is shown.
No black dot: no double
Here is a two beside a cell with no dot between them. Because every black dot is marked, this bare edge cannot be a doubling pair.
2 and 4 need a black dot
Four is double two. If four went here, the pair would need a black dot. There is none, so four is out.
Consecutive may still work
Three is consecutive with two, but that is a white-dot relationship. Only black dots were declared complete, so this rule does not remove three.
Read the transcript
A black Kropki dot joins digits where one is double the other. This puzzle says every black dot is shown. Here is a two beside a cell with no dot between them. Because every black dot is marked, this bare edge cannot be a doubling pair. Four is double two. If four went here, the pair would need a black dot. There is none, so four is out. Three is consecutive with two, but that is a white-dot relationship. Only black dots were declared complete, so this rule does not remove three.
