Primes vs RiddleSum

Have fun with prime numbers, 2 different ways to play, 3 levels of complexity each. The goal is to make the sum of every row and column be a prime number. Roll The Prime This is a game where you need lots of luck and some skill. Place randomly generated numbers on the grid, make the sum of every row and column be a prime number. Even with superb skills, your chance of successfully completing the game is less than 25%. Puzzle Primes This is a game of skill and mental math. Swap numbers on the grid to make the sum of every row and column a prime number, it may take you 5 moves or 15 moves but every puzzle has a solution.

RiddleSum is a clean and addictive number puzzle where your goal is to balance every row and column. Pick the right numbers, remove the wrong ones, and make all sums match the clues on the edges. Simple at first glance - surprisingly deep once you start playing. Every puzzle has one single correct solution. Analyze, eliminate, and find the perfect combination that works in all directions at the same time. It’s a great way to sharpen your logic, focus, and mental math skills. How to play: • Check the target sums for each row and column. • Cross out numbers that can’t be part of the solution. • Keep only the numbers that complete the total. • Solve boards from 3×3 up to 9×9. Features: • Hundreds of handcrafted number puzzles. • Clean and minimal design that feels relaxing. • Helpful hints when you’re stuck. • No timers, no pressure — solve at your own pace. • A subtle daily workout for your brain and arithmetic. If you love smart logic puzzles and satisfying “aha!” moments, RiddleSum is perfect for your daily brain routine. Enjoy solving beautifully simple number challenges anywhere, anytime.