How to Play SUMS

SUMS is a free daily number logic puzzle. Fill a grid by placing numbers in order using adjacent sums. Mini SUMS is 5×5; Full SUMS is 7×7. New puzzles publish daily at midnight Eastern Time.

Rules, step by step

1. Read the starting grid. Gray numbers come with the puzzle, including 1, 2 and 3. Black squares are walls. Every other empty square gets a number from you.
2. Count up in order. Your first number is 4, then 5, then 6. Numbers go in order and you can't skip ahead.
3. Tap a chain that adds up to the next number. Each number in the chain must touch the one before it, and diagonals count. Your first move is usually 1 + 3 = 4.
4. Place it next to the end of your chain. Tap an empty square touching the last number in your chain. The new number appears there.
5. Earn the gray numbers. When the count reaches a gray number, a chain of numbers touching it has to add up to it, and then the count moves on. Plan ahead so that chain will exist, and undo if it can't.
6. Fill every square. The puzzle is solved when every square that isn't a wall has a number. Undo and Hint are always there if you get stuck.