The mentalfloss.com Brain Game opens a new week with a Monday Math Square. I tried to include a few 11s to coincide with our 11-on-12 theme. Good luck! The nine white squares inside the main red grid should be filled with the digits 1 through 9. Each digit should appear only once in this main grid (the red square). Place the digits 1 through 9 in their correct spots so that the mathematical equations work both across and down. Here is the SOLUTION. NOTE: These puzzles... READ ON

To begin a new week, the mentalfloss.com Brain Game brings you a new Monday Math Square. Enjoy! The nine white squares inside the main red grid should be filled with the digits 1 through 9. Each digit should appear only once in this main grid (the red square). Place the digits 1 through 9 in their correct spots so that the mathematical equations work both across and down. Here is the SOLUTION. NOTE: These puzzles rarely (but occasionally) have alternate solutions that fit... READ ON

As has become custom on Monday, today's mentalfloss.com Brain Game is a new Monday Math Square. NOTE: We're actively working on ways to make the Math Square (and other Brain Game puzzles) interactive so that you can solve them on-screen. We'll keep you posted on the results. Good luck with today's puzzle! The nine white squares inside the main red grid should be filled with the digits 1 through 9. Each digit should appear only once in this main grid (the red square). Place the digits 1 through 9 in... READ ON

Today's mentalfloss.com Brain Game is another new Monday Math Square. Enjoy! The nine white squares inside the main red grid should be filled with the digits 1 through 9. Each digit should appear only once in this main grid (the red square). Place the digits 1 through 9 in their correct spots so that the mathematical equations work both across and down. Here is the SOLUTION. NOTE: These puzzles rarely (but occasionally) have alternate solutions that fit the rules. If you... READ ON

Monday Monday, so good to me... Enjoy a new Monday Math Square for today's mentalfloss.com Brain Game. Good luck! The nine white squares inside the main red grid should be filled with the digits 1 through 9. Each digit should appear only once in this main grid (the red square). Place the digits 1 through 9 in their correct spots so that the mathematical equations work both across and down. Here is the SOLUTION. NOTE: These puzzles rarely (but occasionally) have alternate... READ ON

Here's a new Monday Math Square for today's mentalfloss.com Brain Game. Enjoy! The nine white squares inside the main red grid should be filled with the digits 1 through 9. Each digit should appear only once in this main grid (the red square). Place the digits 1 through 9 in their correct spots so that the mathematical equations work both across and down. Here is the SOLUTION. NOTE: These puzzles rarely (but occasionally) have alternate solutions that fit the rules. If you... READ ON

You'll find the rare "double divide" in the middle horizontal row of the Monday Math Square for today's mentalfloss.com Brain Game. Good luck! The nine white squares inside the main red grid should be filled with the digits 1 through 9. Each digit should appear only once in this main grid (the red square). Place the digits 1 through 9 in their correct spots so that the mathematical equations work both across and down. Here is the SOLUTION. NOTE: These puzzles rarely (but... READ ON

Get ready for the next entry in our long-running series of Monday Math Squares for the mentalfloss.com Brain Game. Good luck! The nine white squares inside the main red grid should be filled with the digits 1 through 9. Each digit should appear only once in this main grid (the red square). Place the digits 1 through 9 in their correct spots so that the mathematical equations work both across and down. Here is the SOLUTION. NOTE: These puzzles rarely (but occasionally) have... READ ON

Please enjoy today's mentalfloss.com Brain Game, entry #103 in the Monday Math Square series. Good luck! The nine white squares inside the main red grid should be filled with the digits 1 through 9. Each digit should appear only once in this main grid (the red square). Place the digits 1 through 9 in their correct spots so that the mathematical equations work both across and down. Here is the SOLUTION. NOTE: These puzzles rarely (but occasionally) have alternate solutions that fit the rules. If... READ ON

The eye chart with the big "E" on top is called a Snellen Chart.