- Puzzles9 shared a brain teaser with nine squares, one missing a number.
- The challenge is to figure out how the numbers are related and fill in the missing one.
- Can you solve it? Scroll down for the answer.

Who can resist a good mathematical brain teaser?

Similar to Sudoku, this puzzle created by Puzzles9 consists of a rectangle with nine squares, each containing a number except for the bottom right square.

Filling in the missing number requires determining the pattern of how the numbers are related to each other and following it through.

Can you figure out what the missing number is?

If not, don’t worry. Here’s how to find the answer.

Read the first two rows of numbers horizontally, each as one number – 289 and 324.

The pattern is that 17 x 17 = 289 and 18 x 18 = 324. So it stands to reason that the bottom row will be 19 x 19 = 361. Therefore, the missing number is one.

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