Frame Sudoku follows the same rules as regular Sudoku in that each row, column and block must contain
one of the numbers from "1" to "9". No number may appear more than once in any row, column, or block.
It differs in that it introduces numbers surrounding the grid - each number is the sum of the three nearest digits in that row or column.
For example, in the puzzle to the right, the three cells shaded grey must add up to 21 and those shaded yellow must sum 6.
All puzzles are solvable by pure logic alone - no guessing required.
Be sure to read the walkthrough first.
You may find these puzzles challenging - remember you can use the "Solve a Cell" feature to help you along.