The case notes
How a Sandwich sum works
The outside clue is the sum of the digits strictly between 1 and 9 in its row. Watch a worked example, then try the idea in a puzzle.
Put it into practice
Find 1 and 9
In a Sandwich puzzle, an outside clue describes a row or column. Find the one and the nine. They are the two ends of the sandwich.
Count only what is between
Only the cells between those ends count. The one and nine themselves do not. Here, that means just these two cells.
10 − 3 = 7
The clue says ten. One inside cell is already three, so the other must be seven. Three and seven make ten.
1 and 9 mark the ends
The clue is about the filling, wherever the one and nine happen to be. The digits outside them are not part of its sum.
Read the transcript
In a Sandwich puzzle, an outside clue describes a row or column. Find the one and the nine. They are the two ends of the sandwich. Only the cells between those ends count. The one and nine themselves do not. Here, that means just these two cells. The clue says ten. One inside cell is already three, so the other must be seven. Three and seven make ten. The clue is about the filling, wherever the one and nine happen to be. The digits outside them are not part of its sum.
