Paul Erdős International Math Challenge

The ABACUS International Math Challenge was launched in 1997 by Tivadar Divéki, head of Grace Church School’s Science Department. In September, 2015, we proudly changed the name of our program to Paul Erdős International Math Challenge.  The program is based on a printed journal for gifted students, originating in Hungary over 100 years ago. Participants over the years included Edward Teller, Leo Szilárd and other notables in physics, computer science and mathematics. This program is designed for students of all abilities and demonstrates that mathematical talent can be stimulated and developed through individual attention, instant feedback and challenging subject matter with flexible levels of difficulty.

The Internet has made this program available to students around the world. Every month, eight problems are posted for each of three age groups. Students are asked not only to solve the problems but also to present the reasoning in their solutions. If a student submits an incorrect solution or is simply having trouble with a problem, a teacher will offer hints as to how to go about solving the problem, giving students multiple chances to succeed.

The annual Paul Erdős International Math Challenge in this academic year runs from September, 2016 through April 30th, 2017.

Categories & Contacts
Group A – 3rd and 4th graders
Group B – 5th and 6th graders
Group C – 7th and 8th graders

Starting this year, the Sharma Kamala Educational Trust is sponsoring the participation of students from India. So, if you are a student living in India, please, send your solutions to:

Group A from India  – 3rd and 4th graders
Group B from India – 5th and 6th graders
Group C from India – 7th and 8th graders

In your first e-mail, please indicate your name, your grade/age, the name of your school, and the city where you live. Make sure that you indicate the number of the problem you are responding to. For proper identification, every e-mail you send should include your name.

The solution to a problem should include the results and your reasoning. Make sure that you try to find all the possible solutions for a problem. Your reasoning has to be given in English, but do not be discouraged if English is your second language. If we have a question about your answer, we will contact you.
Try to send your answers by the last day of the month for the posted problem, however solutions to any of the problems will be accepted until April 30, 2017. (You are welcome to participate in higher grade groups by solving their problems.)

You get five points for a thorough solution with reasoning; fewer points for a partial solution or solution with no reasoning, and more points if you find additional different solutions or prove more than required.
You may earn extra points if you design your own problems and they get posted in the challenge. So, try to make up some problems and solve them.


Schools and teachers across the U.S. and Canada regard Tammy Worcester Tang as one of our country’s leading education technology experts ( She provides valuable insight to the development of our online games and apps and is co-writing a book with Greg on word problems for grades K-2 that will be published by Teacher Created Materials.


Four years ago, Greg Tang launched this website from a small coffee shop in Arlington, Massachusetts as a way to make his books, games, and teaching materials available to more students and teachers. Today, it is used by classrooms around the world to supplement their math curriculums and develop better computational and problem-solving skills.

Every activity has been designed to teach a critical skill or strategy while providing the repetition and practice required for mastery. Most importantly, each stays true to the ideal that teaching and learning should be clever and fun. None of our games use non-math activities to incent students to play. The hook of every game is the math itself and students spend every second doing math. It is all math, all the time.

Today, we are working harder than ever to improve our site. Soon, we’ll be adding instructional videos, organizing more national events like our Winter Math Challenge and March MATHness Tournament, and adding multiplayer games that offer kids an exciting alternative to non-educational video and computer games. is an important part of Greg’s mission to help children of all ages, abilities and backgrounds. Since 2013, he has made his site free to everyone and continues to support it through his teaching and writing. We hope you and your students will continue to use and share our site both at school and at home.


Math WebQuests

Math Webquests enable online explorations in mathematics. Each webquest is a unique exploration designed to be fun and engaging. Webquests make connections between mathematics and the real-world. Students who embark on webquests become engaged in both finding information and learning from it. Give it a try!


Exponents and Scientific Notation

Scientists use math to express relationships and to measure the size and distance of objects. For example, scientific notation is used to express a planet’s distance from the sun, or the size of bacteria. Explore these connections!

Integers and Science

Explore the connections between integers and science. The boiling and freezing point of liquids, the melting and freezing points of solids, and the temperature of planets, are all expressed as integers. Learn more.

Mathematics and Climate

Scientists use mathematics to better understand oceans, the atmosphere, and polar ice caps. Explore climate change, and how it is monitored.

Mathematics and Sports

Math plays an important role in sports! We have four webquests on Win-Loss Percentage, graphing data for Olympics and Super Bowls, Batting Average and ERA, and the NBA Draft Lottery. Explore this exciting group of webquests.

Mathematics and the Summer Olympics

The 2012 Summer Olympic Games are being held in London from July 27 to August 12. Discover the exciting connections between math and the Summer Olympic Games with this quest!

Number Theory

Are you ready to help your garden grow using multiples? Count with Fibonacci? Bake with Eratosthenes? We invite you toexplore these fun topics!

Percent in Daily Life

Students often question the need to learn mathematical topics. Whether you are shop, work, or play sports, you are using percent. Learn more!

Pi Day Celebration

Pi Day is celebrated around the world on March 14. Explore the history and meaning of Pi, and choose activities to Celebrate Pi Day!


Scientists in Schools Workshop Catalogue

2016-17 Workshop Catalogue

scientists-in-schoolsKindergarten to Grade 8 science, technology, engineering and math (STEM) programs




Backyard Bugs – Buzz about Bees – I Can Be a Scientist – Magnet Magic for Little Explorers – Sensational Science – Simply Marvellous Machines – There’s No Place like Home! – Water Fun for Kindergarten Scientists – Winter Wonders! – Young Friends of the Earth


  • Primary: Animal Coverings And Adaptations* – Let It Flow: Air And Water – Soil: It’s Too Important To Be Treated Like Dirt!
  • Junior: Celestial Sleuths – Conserve your Energy – Don’t take Rocks for Granite – Energy: The Power to Change
  • Intermediate: Groundwater Investigations – Hot Stuff!


  • Primary: Food Chains* – Keep Track: Animal Autographs* – Never say Ugh to a Bug* – Ocean Habitats and Adaptations – Plants Do Amazing Things
  • Junior: Battles in the Tropical Rainforest* – Body Works – Classy Critters – Habitats and Communities
  • Intermediate: Cell Explorers: Investigating Cell Structure and Function


  • Primary: Math: It Counts*
  • Junior: Fractions In Action* – Math Builders: Math From The Ground Up*
  • Intermediate: Math Is My Business*


  • Primary: Energy Makes It Happen – Force, Of Course! – Looking at Liquids
  • Junior: Electricity: Get Charged – Light Up Your Life – Sound is Music to my Ears – What in the World is Matter?
  • Intermediate: Close Encounters of a Chemical Kind – Fluid Power


  • Primary: Kitchen Chemistry for Curious Kids* – Microscopy: More than Meets the Eye* – Sense and Sense-Abilities – Toys and Technology: Fun with Physics*
  • Junior: Adventures in the Bone Zone* – Brainstorm: Journey to the Centre of the Mind* – Clued into Forensic Science* – Charge Up Your Energy*
  • Intermediate: And the Band Played On* – Gene: How Do You Pass It On* – Global Climate Change*


  • Primary: Get Moving with Toys! – Move It! – Structures: Stable and Strong – Structures: Under Construction
  • Junior: Air and Flight – Gearing Up: Fun with Pulleys and Gears – May the Force be with You
  • Intermediate: Engineering Challenges – Systems at Work

ONTARIO : PROGRAMME EN FRANÇAIS – Offert seulement à Ottawa

Maternelle et jardin : Je peux être un scientifique – À la découverte des machines simples!

  1. 1re : Avec l’énergie, c’est possible! – Les animaux : ruses et environnement* – Structures: en chantier!
  2. 2e année : Air et eau : à la source de la vie – Ça bouge! – Jetons un coup d’oeil aux liquides – Les animaux : ruses et environnement*
  3. 3e année : Aventures dans le monde des os* – Le sol : un trésor sous nos pieds – Structures : stables et solides – Tours de force!
  4. 4e année : Aventures dans le monde des os* – Engrenages et poulies : du plaisir garanti! – Illuminez votre vie – Roches et fossiles : faites d’une pierre deux coups!
  5. 5e année : Aventures dans le monde des os* – Le corps humain – Que la force soit avec toi! – Qu’est-ce que la matière?
  6. 6e année : Aventures dans le monde des os* – Des bestioles avec de la classe – L’air et le vol – L’électricité : un sujet électrisant! – La conquête de l’espace