Test your critical thinking skills with a variety of cryptography brain teasers, phrases or expressions "encoded in some way." Solve the teasers provided at this site, and submit your own for others to try!

Sharpen your problem solving, sequencing, and spatial reasoning skills playing this interactive game, Roll The Dice. See how many different paths you can take to end up with the same result.

Sharpen your logic and spatial sense skills while working on this challenge. Solution included.

At this one page web site see if you can solve this puzzle involving the edges of an octahedron. You will definitely need to use your problem solving and spatial reasoning skills for this!

On this one page website sharpen your logic, triangle properties, and pattern recognition skills while working on this challenge. The solution is available to double check your solution.

Using your reasoning skills and the clues provided, try to figure out who is sitting where at this table of six. Check the solution and see if you are correct. You can choose similar games and math problems on this page, or choose math...

Have you ever wondered why manhole covers are round? Believe it or not, there is a logical, mathematical reason. See if you can figure it out in this NCTM Math Challenge for Families activity. A one-page activity with suggested life...

Who turned off the lights? Well, we'll need your help turning them back on. Use logic and reasoning to light up the rooms with the different tools provided. Are you bright enough to complete this challenging puzzle game?

Use this website to help you hone your critical thinking and math-problem solving skills. Learn what "Negation," is and how it applies when you are working on mathematical problems and sentences.

A lesson based on the story, "Oliver's Fruit Salad," where students explore the concept of proportional reasoning through modeling, student sharing, and questioning. A great introductory lesson for this concept that is sure to engage...

This resource presents an interesting challenge for the serious mathematician with strong reasoning skills. Explore proportional reasoning, probabilities, fractions, and ratios in this challenge to figure out if you always get six hours...

Hook a is beautifully unique and simple game that will keep you thinking for hours. The goal is to remove the hooks in the correct order, so they do not get "hooked" on anything.

Robo Trobo is a problem solving game for kids of all ages. Kids will need to guide Robo through complex puzzles in order to complete the different levels. Have fun and think outside the box!

Can you guess the correct number between 1 and 99 in less than 30 tries? Play this fast paced, interactive game that tests your number sense and reasoning skills. If your are a great guesser, your name will be posted.

On this one page website sharpen your logic, geometry, spatial thinking, and problem solving skills while working on this challenge. The solution is available to double check your solution.

A comprehensive lesson on algebraic thinking where students create and identify patterns using proportional reasoning. Research based, this lesson includes technology connections, items for discussion, and extension activities.

Find a collection of colorful, interactive, challenging puzzles: Hexnut Jr., Quintapaths, Roundominoes, and others.

In association with NASA, LineUp With Math presents problem sets which 'enable students to explore and apply decision-making and reasoning skills, specifically to resolve distance-rate-time conflicts in air traffic control'. An...

This tutorial for students new to algebra provides explanations, definitions, examples, and practice problems. The practice tests cover topics such as real numbers, fractions, equations, graphing, and exponents.

A geometry problem for students to use their mathematical reasoning skills to explain a right triangle property.

On this one page website sharpen your logic and problem solving skills while working on this challenge. The solution is available to double check your solution.

Sharpen your problem solving and strategy skills playing this interactive game, Fifteen. The rules are simple but the game requires some thinking if you want to beat the computer. There is a "Printable Page," link if you want to print it...

Your reasoning skills will come in handy as you find solutions to these "sock" problems. Solutions are available on this one page website.

Sharpen your problem solving and strategy skills playing this Somali game, Pumpkin Patch. The rules are simple but the game requires some thinking. There is a "Get Printable Page," link at the top to print out the materials you need.