Normal sudoku rules apply. For each line, digits have an equal sum within each box the line passes through. eg For the line starting in r6c1, the sum of the box 4 digits must equal the sum of the box 7 digits ie r6c1 + r6c2 = r7c2 + r8c2 + r8c3.
Normal sudoku rules apply. For each line, digits have an equal sum within each box the line passes through. eg For the line starting in r6c1, the sum of the box 4 digits must equal the sum of the box 7 digits ie r6c1 + r6c2 = r7c2 + r8c2 + r8c3.