The case notes
How a palindrome line reads
Digits on the marked line read the same from either end. Watch a worked example, then try the idea in a puzzle.
Put it into practice
Read it both ways
This is a Sudoku with a palindrome line. Read the digits along the line from one end, then read them back from the other.
The ends match: 8 and 8
The first cell is eight. Its partner at the opposite end must also be eight. The ends match.
Each pair mirrors
Step one cell in from each end. There is a three on this side, so the matching cell on the other side is three too.
8 · 3 · 5 · 3 · 8
The middle cell pairs with itself. Now the line reads eight, three, five, three, eight in either direction.
Read the transcript
This is a Sudoku with a palindrome line. Read the digits along the line from one end, then read them back from the other. The first cell is eight. Its partner at the opposite end must also be eight. The ends match. Step one cell in from each end. There is a three on this side, so the matching cell on the other side is three too. The middle cell pairs with itself. Now the line reads eight, three, five, three, eight in either direction.
