CAROL’S TIPS

BEGIN by looking for two-cell groups, or cages. Low totals are great clues: a ‘4’ must comprise a 3 and a 1. The same applies to a three-cell cage totalling ‘6’ — it must contain 1, 2 and 3. Bigger totals can be revealing, too. A two-cell cage that adds up to ‘11’ cannot contain a 1, because there’s no 10 in Sudoku. A two-cell group totalling 16 has to be a 9 and a 7. Another giveaway is the magic number 45 . . . that’s what you get when you add all the numbers from 1 to 9. And that’s the total of every bold block. This provides a crucial clue.