Uploaded July 2026 | Updated September 2026, 2 weeks ago
Can you fill a 3x3 grid using the numbers 1 to 9 so that every row, column, and diagonal adds up to the exact same sum? There is a logical way to crack this and once you see it, you will never need to guess again.
In this video we discover why the magic sum must always be 15 when using numbers 1 through 9, how to figure out which number must go in the center, and why certain numbers can only go in the corners while others belong on the edges. Follow along as we use pure logic to place each number one by one until the entire square is solved. We also explore how this same method works for any set of consecutive numbers, not just 1 to 9. And at the very end, we look at an incredible 4x4 magic square carved into the walls of a Jain temple in Khajuraho, India over a thousand years ago.
Courses on Khan Academy are always 100% free. Start practicing and saving your progress now!
khanacademy.org/math/class-7-ncf/x063f95a40c290960:number-play?lang=en
Timestamps:
0:00 - The Magic Grid Puzzle
1:05 - Why Random Guessing Fails
1:49 - What Is a Magic Square
2:54 - Finding the Magic Sum (45 / 3 = 15)
4:32 - Why 9 Cannot Be the Center
5:37 - Proving 5 Must Be the Center
6:32 - Corner Numbers vs Edge Numbers
7:27 - Placing the Remaining Numbers Logically
8:44 - Completing the Magic Square
9:28 - The Chautisa Yantra: India's Ancient 4x4 Magic Square
Khan Academy India is a nonprofit organization with the mission of providing a free world-class education for anyone anywhere. We have videos and exercises that have been translated into multiple Indian languages and 15 million people around the globe learn on Khan Academy every month.
Support Us: india.khanacademy.org/donate
Can you fill a 3x3 grid using the numbers 1 to 9 so that every row, column, and diagonal adds up to the exact same sum? There is a logical way to crack this and once you see it, you will never need to guess again.
In this video we discover why the magic sum must always be 15 when using numbers 1 through 9, how to figure out which number must go in the center, and why certain numbers can only go in the corners while others belong on the edges. Follow along as we use pure logic to place each number one by one until the entire square is solved. We also explore how this same method works for any set of consecutive numbers, not just 1 to 9. And at the very end, we look at an incredible 4x4 magic square carved into the walls of a Jain temple in Khajuraho, India over a thousand years ago.
Courses on Khan Academy are always 100% free. Start practicing and saving your progress now!
khanacademy.org/math/class-7-ncf/x063f95a40c290960:number-play?lang=en
Timestamps:
0:00 - The Magic Grid Puzzle
1:05 - Why Random Guessing Fails
1:49 - What Is a Magic Square
2:54 - Finding the Magic Sum (45 / 3 = 15)
4:32 - Why 9 Cannot Be the Center
5:37 - Proving 5 Must Be the Center
6:32 - Corner Numbers vs Edge Numbers
7:27 - Placing the Remaining Numbers Logically
8:44 - Completing the Magic Square
9:28 - The Chautisa Yantra: India's Ancient 4x4 Magic Square
Khan Academy India is a nonprofit organization with the mission of providing a free world-class education for anyone anywhere. We have videos and exercises that have been translated into multiple Indian languages and 15 million people around the globe learn on Khan Academy every month.
Support Us: india.khanacademy.org/donate
