APOLOGIES: I made an error in the first Math Square today. This is a revised version that fixes the mistake. Sorry, folks! The next-to-last week of the year opens with today's mentalfloss.com Brain Game, a new Monday Math Square. 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... READ ON

Please enjoy today's mentalfloss.com Brain Game, entry #101 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

Good luck with today's mentalfloss.com Brain Game. It's hard to believe that we're passing the century mark with the Monday Math Square. It seems as popular as ever, though, so here's to 200! 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.... READ ON

As promised, here's a brand 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

It's the beginning of a new week, and that means it's time for a new Monday Math Square here at 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

Good luck unraveling today's Monday Math Square at the mentalfloss.com Brain Game! 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 find one of... READ ON

Please pay attention while traveling today, and keep an eye out for all those excited kids (and adults) who will be out and about for the Halloween holiday. To make sure you're alert, here's a new Monday Math Square at 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... READ ON

Monday Math Square. mentalfloss.com Brain Game. Have at it! 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 find one of these, first make sure that... READ ON

Today's mentalfloss.com Brain Game: a Monday Math Square. 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 you find one of these, first make... READ ON

As promised a new Monday Math Square here at the 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 find one of... READ ON

7-Up was originally called "Bib-Label Lithiated Lemon-Lime Soda."