Today's PUZZLE CLASSIC OF THE DAY

1, 2, 3, 4, 5, 6, 7, 8, and 9 to 100

1, 2, 3, 4, 5, 6, 7, 8, and 9 to 100

Digits 1-9, when added together, produce 45. By replacing one plus with another arithmetic sign, it is possible to get 100. Which plus and with what sign must be replaced?

PREVIOUS 12 DAYS

$5 in Hundred Coins

When Black Bart took the Denver stagecoach for the 13th time, his luck finally ran out. The only cash he found was in the merchant's travel bag, and it was $5, all in coins. There were exactly 100 coins, though not a single nickel or quarter. Can you determine their quantities?

Hourglasses: 5-min Egg

You must boil an egg for exactly 5 mins. All you have is a 3-min and a 4-min hourglasses. How many times will you need to turn each hourglass in order to measure 5 mins?

TriCounting: Isometric Cube

How many triangles are in this figure? Select a triangle and click the "Count" button.

TriCounting: Octahedron

How many triangles are in this figure? Select a triangle and click the "Count" button.

Shifted Top Row

Cut this figure into 2 congruent parts (identical in area and shape, though they can be mirrored) so that each of them includes 2 paperclips.

Mallet into 2 Congruent Parts

Cut this figure into 2 congruent parts (identical in area and shape, though they can be mirrored).

TriCounting: Squared X in Squared X

How many triangles are in this figure? Select a triangle and click the "Count" button.

Shaded Area: Leaf in a Square

Using provided changers, calculate the area of the shaded part.

TriCounting: Bisectors V2

How many triangles are in this figure? Select a triangle and click the "Count" button.

TriCounting: Diamond

How many triangles are in this figure? Select a triangle and click the "Count" button.

Three Crates: Congruent Parts

Cut this figure into 3 congruent parts (identical in area and shape, though they can be mirrored).

TriCounting: Arrow Up

How many triangles are in this figure? Select a triangle and click the "Count" button.

Puzzle Classics are timeless brain teasers that have captivated generations of players worldwide. These traditional puzzles challenge your intellect, creativity, and problem-solving skills through various formats and difficulty levels. From logic grids and spatial reasoning to word play and mathematical challenges, classic puzzles offer something for every type of thinker.


Classic puzzles develop critical thinking abilities that are valuable in everyday life. The beauty of these puzzles lies in their elegant simplicity combined with deep complexity - what appears straightforward at first glance often reveals hidden layers of challenge upon closer examination. Solving classic puzzles requires patience, attention to detail, and the ability to see patterns and connections that aren't immediately obvious.


Traditional puzzles stimulate multiple areas of the brain simultaneously. Whether you're deducing solutions through logical elimination, visualizing spatial relationships, or finding creative workarounds, you're giving your cognitive functions a comprehensive workout. Classic puzzles enhance memory retention, improve concentration, and develop systematic thinking approaches that can be applied to real-world problems.


Mastering classic puzzles builds confidence and resilience. The satisfaction of solving a challenging puzzle after careful analysis and multiple attempts provides a genuine sense of accomplishment. This positive reinforcement encourages persistence when facing difficult tasks in other areas of life, teaching valuable lessons about the rewards of sustained effort and strategic thinking.


Our extensive collection of interactive Puzzle Classics spans numerous categories and difficulty levels, making them perfect for both beginners and experienced puzzle enthusiasts. You can enjoy these timeless challenges repeatedly, discovering new insights each time, and share your favorite puzzles with friends and family members of all ages.


How to approach Puzzle Classics? While each puzzle type has its unique strategies, some universal principles apply. Read the instructions carefully - often the key to solving lies in understanding exactly what's being asked. Look for constraints and rules that might guide your approach. Don't be afraid to experiment with different methods, and remember that sometimes stepping away and returning with fresh eyes can reveal solutions that weren't apparent initially. Practice regularly - like any skill, puzzle-solving improves with consistent effort.


As an interesting historical note, here are 7 fascinating facts about classic puzzles:

- The oldest known puzzle is the "Stomachion," dating back to Archimedes around 200 BC;

- The Rubik's Cube, invented in 1974, has over 43 quintillion possible configurations;

- Sudoku, though associated with Japan, was actually invented by an American architect in 1979;

- Crossword puzzles first appeared in the New York World newspaper in 1913;

- The famous "Tower of Hanoi" puzzle was invented by French mathematician Édouard Lucas in 1883;

- Jigsaw puzzles were originally created as educational tools to teach geography to children;

- Logic puzzles have been used in psychological testing and entrance exams for decades due to their effectiveness in measuring reasoning ability.