Here is a list of all the Problems of the Month that have been posted from January 2016 to December 2024.  
You may view any of the past problems by clicking on the name.

2016

  Date   Name of Problem of the Month Math Needed
January 2016 The New Year Challenge Algebra
January 2016 The 10 Tallest Monuments Algebra, Logic
January 2016 2016 Puzzle Logic
           
February 2016 Math Odd Letter Out Logic
February 2016 Four on the Floor Logic
February 2016 Three Digit Number problem Logic, Arithmetic
           
March 2016 The 10 Square Rectangle Algebra
March 2016 Tic-Tac-Logic Logic
March 2016 Monkey Business Logic
           
April 2016 How Sweet It Is! Algebra
April 2016 Futoshiki Logic, Arithmetic
April 2016 Math Art Logic
           
May 2016 Inheritance Problem Algebra
May 2016 The Square Problem Algebra
May 2016 Cylindrical Fuel Tank Problem Algebra, Geometry, or Calculus
           
June 2016 Six Mix Arithmetic, Logic
June 2016 A Whole Lot in Common Logic
June 2016 Weighted Diagonal Logic
           
July 2016 Nine Digit Number Logic
July 2016 The Missing Link Logic, Arithmetic
July 2016 Three Texas Drovers Algebra
           
August 2016 The Milkman's Puzzle Logic
August 2016 Chess Problem (Revisited) Logic
August 2016 Which Barrel was left? Logic, Arithemtic
           
September 2016 The 9 Square Rectangle Algebra
September 2016 10-Digit Number Problem Logic
September 2016 The Tower of London (Part 1) Logic
           
October 2016 The Leaning Tower of Pisa Algebra
October 2016 How Old is Pocahontas? Algebra
October 2016 Against the Wind Algebra
           
November 2016 The Tower of London (Part 2) Logic
November 2016 The Hat that Didn't Sell Logic
November 2016 Thanksgiving Crossword Puzzle Logic
           
December 2016 Sierpinski's Christmas Tree Algebra
December 2016 Christmas Present Puzzle Algebra
December 2016 Christmas Tree Puzzle Algebra
December 2016 Christmas Bonus -- The Pleacher Family Christmas Logic

2017

  Date   Name of Problem of the Month Math Needed
January 2017 The New Year Challenge Algebra
January 2017 Math Before Breakfast Algebra
January 2017 Year Without Brackets Algebra
           
February 2017 The Telephone Number Algebra
February 2017 Cowboy Puzzler Algebra
February 2017 A Painted House Algebra
           
March 2017 String Problem Algebra
March 2017 Rectangular Parallelepiped Problem Algebra, Geometry
March 2017 Street Closure Problem Logic
           
April 2017 Lock Problem Logic
April 2017 Area Problem Algebra, Geometry
April 2017 Clock Problem Logic
           
May 2017 Three Walkers Algebra
May 2017 College Math Algebra
May 2017 The Three Thieves Algebra
           
June 2017 As Easy As A, B, ... Arithmetic
June 2017 The Three Thieves (Part 2) Algebra
June 2017 The Lock Problem (Part 2) Algebra
           
July 2017 Prime Time Arithmetic, Logic
July 2017 CalcuDoku Algebra
July 2017 Game Devisers Logic
           
August 2017 Balanced Equations Algebra, Logic
August 2017 Cinematic Conversions Logic, Arithmetic
August 2017 Petite Circle-Sum Walkthrough Logic, Arithmetic
           
September 2017 Mr. P's Grandchildren Algebra
September 2017 NFL Wackie Wordies Logic
September 2017 A Radical Equation Algebra
           
October 2017 Generosity after the Hurricanes Arithmetic, Algebra
October 2017 Russian Army motorcyclists Geometry
October 2017 Another A and B problem Algebra
           
November 2017 Addition Problem Logic, Arithmetic
November 2017 Picture Magic Square Logic, Algebra
November 2017 Blowin' in the Wind Algebra
           
December 2017 Christmas Tree Puzzle Algebra
December 2017 Math Art Logic
December 2017 Meet 16 Algebra

2018

  Date   Name of Problem of the Month Math Needed
January 2018 The New Year Challenge Algebra
January 2018 New Year Magic Square Logic, Arithmetic
January 2018 2018 Multiplication Problem Logic, Arithmetic
           
February 2018 David Jones' Locker Logic, Arithmetic
February 2018 Two-Player Game Logic, Arithmetic
February 2018 De Morgan's Age Problem Logic, Arithmetic
           
March 2018 Super Bowl Party Game Logic, Arithmetic
March 2018 Women's Basketball Polls Logic, Arithmetic
March 2018 Moving Walkways Logic
           
April 2018 April Fools Logic, Arithmetic
April 2018 Cross Number Puzzle Logic, Arithmetic
April 2018 Top Ten Colleges Logic
           
May 2018 Isosceles Triangle Problem Algebra
May 2018 Math Scramble Logic
May 2018 World Tour Logic
           
June 2018 As Easy As A + B + C Algebra
June 2018 As Easy As Pi Algebra
June 2018 Skyscrapers Logic
           
July 2018 Distance Problem Geometry
July 2018 Loco Sudoku Logic
July 2018 Dividing the Spoils Algebra
           
August 2018 Cross Math Puzzle Algebra, Logic
August 2018 What Fraction? Geometry
August 2018 Three Lighthouses Logic
           
September 2018 Mr. P's Phone Number Arithmetic, Logic
September 2018 MOD Pizza Algebra, Geometry
September 2018 Geometric Shapes Search Geometry
           
October 2018 Missing Mathematicians Logic
October 2018 The 416 Fire Arithmetic, Logic
October 2018 Chess Puzzler (5 pieces) Logic
           
November 2018 Four Digit Number Trick Arithmetic, Logic
November 2018 SUMOKU Arithmetic, Logic
November 2018 Change for a (half) Dollar Arithmetic, Logic
           
December 2018 Christmas Tree Puzzle Algebra
December 2018 Mince Pies Logic
December 2018 Sum and Product Algebra

2019

  Date   Name of Problem of the Month Math Needed
January 2019 The New Year Challenge Algebra
January 2019 Chess Puzzler (8 Queens) Logic
January 2019 Boeing 747 Arithmetic
           
February 2019 Bucket Problem Arithmetic, Logic
February 2019 Stewart's Birthday Cake Geometry, Algebra
February 2019 Math Doublets Logic
           
March 2019 Elephant Drinking Problem Arithmetic
March 2019 Jersey Pi Problem Logic
March 2019 Scrabble Squares Arithmetic, Logic
           
April 2019 Laying Eggs Logic
April 2019 Easter Word Cross Logic
April 2019 Easter Egg Hunt Algebra
           
May 2019 Bucket Problem #2 Geometry
May 2019 Trading in the Philippines Arithmetic, Logic
May 2019 Longfellow's Bees Algebra
           
June 2019 Family Age Problem Algebra
June 2019 The monk and the bridges Logic
June 2019 TV Viewing Distance Algebra, Geometry
           
July 2019 Dividing Apples Logic
July 2019 Money Problems Algebra
July 2019 Prison Problem Logic
           
August 2019 Insulin Pen Logic
August 2019 Fill in the Squares Logic
August 2019 The Envelope Problem Logic, Arithmetic
           
September 2019 NFL Passer Rating Algebra
September 2019 Dice Roulette Probability
September 2019 Easy as 1, 2, 3! Algebra
September 2019 Corporate Greed in America Arithmetic
           
October 2019 How Old is the Boss? Algebra
October 2019 The Spider and the Fly Geometry
October 2019 Skyscrapers Part 2 Logic
           
November 2019 The Rocky Mountain Lobos Algebra
November 2019 Prime Choices Logic, Arithmetic
November 2019 Number Trick Algebra
           
December 2019 Christmas Tree Puzzle Algebra
December 2019 As Easy as A, B, and C Algebra
December 2019 Kopek Problem Logic

2020

  Date   Name of Problem of the Month Math Needed
January 2020 The New Year Challenge Algebra
January 2020 Mathematical Roundabouts Logic
January 2020 The Odometer Puzzle Algebra
           
February 2020 Train Meeting Algebra
February 2020 Decoding Messages Logic
February 2020 C.S.U. Volleyball Algebra
February 2020 Mass Shootings in 2019 Arithmetic
           
March 2020 Food Bank Truck Algebra
March 2020 Calculus Tag-A-Long Calculus, Logic
March 2020 Test Problems Algebra
           
April 2020 Letter By Letter Logic
April 2020 Math Fill Ins Logic, Math Definitions
April 2020 Coronavirus in Colorado Algebra, Precalculus
           
May 2020 Parking Problem Algebra
May 2020 Pentagon Problem Geometry
May 2020 Getting from A to B Logic
           
June 2020 Different Rectangles Part 1 Logic
June 2020 Numbrix Logic
June 2020 8 Easy Equations Algebra
           
July 2020 Different Rectangles Part 2 Logic
July 2020 Arby's Coupons Logic
July 2020 SUM-THING MISSING Logic
           
August 2020 Different Rectangles Part 3 Logic
August 2020 The Prayer Circle Problem Geometry, Trigonometry
August 2020 How Many Pages? Logic, Arithmetic
           
September 2020 Presidential Golf Arithmetic
September 2020 Dividing the Meal Logic, Arithmetic
September 2020 Numbers Puzzle Logic, Arithmetic
September 2020 A Biblical Treasure Hunt Algebra, Geometry, Trig, Logic
           
October 2020 Five Digits Logic, Arithmetic
October 2020 Smallest Integer Logic, Algebra
October 2020 Hiroimono Logic
October 2020 Trump's False Statements Algebra
           
November 2020 Filling A Cistern Algebra
November 2020 Your (Math) Word Against Mine Logic
November 2020 Political Arithmetic Algebra
November 2020 RR Bridge Part 1 Logic, Prealgebra
           
December 2020 Holiday Trip Logic
December 2020 Wrapping Paper Problem Calculus
December 2020 Decode a message Logic, Magic Squares
December 2020 RR Bridge Part 2 Algebra
December 2020 A Christmas Message Algebra
           

2021

  Date   Name of Problem of the Month Math Needed
January 2021 The New Year Challenge Logic, Algebra
January 2021 Interesting Sums Logic
January 2021 Knight Life Logic, Chess
January 2021 Pythagorean Theorem Days Logic, Geometry
January 2021 A problem from Bhaskara's Lilavati Algebra
           
February 2021 Hiroimono Part 2 Logic
February 2021 Math Boggle Logic
February 2021 NBA Playoff Logic, Algebra
February 2021 Prime Clock Logic, Algebra
           
March 2021 Pie Thoughts Logic
March 2021 Chess Problem Statistics
March 2021 Arithmetic Sequences Algebra, Logic
March 2021 Magic Circles Logic
           
April 2021 Pool Problem Geometry
April 2021 COVID-19 Deaths Arithmetic
April 2021 Easter Egg Hunt Logic
April 2021 Place Setting Problem Algebra
April 2021 Snowtime in Colorado Algebra, Geometry
           
May 2021 Friends in Far Places Logic
May 2021 Go Jump in the Lake Geometry
May 2021 Sequence Problem Algebra
May 2021 Geometry Problem Geometry
           
June 2021 Apartments Logic
June 2021 Mr. P and his grandson Logic
June 2021 Big Number Problem Logic
June 2021 Consecutive Fibonacci Numbers Algebra
June 2021 Sooley Problem Algebra
           
July 2021 Dots in a grid Geometry
July 2021 Money Problem Algebra
July 2021 Oxford Problem Algebra
July 2021 Trains Logic
           
August 2021 Carpenty Problem Logic, Algebra
August 2021 Mystery Numbers Logic
August 2021 Triangle Problem Logic, Geometry, Calculus
August 2021 Inner Circles Logic
           
September 2021 Circle Problem Geometry
September 2021 Square Problem Algebra, Geometry
September 2021 Egg Problem Algebra
September 2021 Window Problem Algebra, Geometry
           
October 2021 What's the Angle? Geometry
October 2021 Travel Problem Algebra
October 2021 Was It A Cat I Saw? Logic
October 2021 Cross Math Puzzle Logic, Arithmetic
           
November 2021 Math Blocks Logic
November 2021 Blackjack Balancing Act Logic, Algebra
November 2021 Tiling Problem Algebra, Geometry
November 2021 Too Many Choices Algebra
           
December 2021 Christmas Message Algebra
December 2021 Carom Billiard Table Algebra, Logic
December 2021 The Smaller Number Algebra
December 2021 Christmas Word Cross Logic
           

2022

  Date   Name of Problem of the Month Math Needed
January 2022 The New Year Challenge Logic, Algebra
January 2022 Incenter of a Triangle Geometry
January 2022 Square Routes Logic
January 2022 1876 M.I.T. Exam question Algebra
           
February 2022 Math Blocks Part 2 Logic
February 2022 Pepper Problem Logic, Algebra
February 2022 Truth Tellers and Liars Logic
February 2022 Tile Problem Geometry, Algebra
           
March 2022 Venn Diagram Mystery Logic
March 2022 Dirty Dozen Balancing Act Logic, Algebra
March 2022 Number Problem Algebra
March 2022 Celebrations in India Logic
           
April 2022 Rectangle Problem Algebra, Geometry
April 2022 Cable Search Logic
April 2022 Magic Hexagon Logic, Arithmetic
April 2022 Digits Problem from 1915 Algebra
           
May 2022 Square Root Problem Algebra
May 2022 Magic Square Algebra
May 2022 Tic Tac Toe -- Math Style Logic
May 2022 Goat Grazing by Gazebo Geometry, Trigonometry
           
June 2022 Time the Two Skaters Algebra
June 2022 Alphabetical Numbers Logic
June 2022 Divisible by 7 Algebra
June 2022 Ladder Problem Geometry
           
July 2022 The Tortoise and the Hare Algebra
July 2022 Banneker's Cattle Problem Algebra
July 2022 Jean and Jane Logic
July 2022 July 4th Parade Logic
           
August 2022 OSLO Logic
August 2022 Fill the Bucket Algebra
August 2022 Triangle Problem Geometry
August 2022 Cat and Turtle on a Table Algebra
           
September 2022 FoCo Traffic Problem Logic
September 2022 Ten Circles in a "Pyramid" Geometry
September 2022 Bat and Ball Algebra
September 2022 Goal Post Multiplication Arithmetic, Logic
           
October 2022 Cross Math Puzzle Logic, Arithmetic
October 2022 Zero Power Algebra
October 2022 Hot Air Balloon Geometry
October 2022 Pumpkin Patch Problem Geometry, Algebra
           
November 2022 Basketball Problem Logic, Arithmetic
November 2022 Carol Pleacher Algebra
November 2022 Mean / Median Algebra
November 2022 Number Cross Sums Logic
           
December 2022 Sum Christmas Trees Logic, Arithmetic, Algebra
December 2022 The Island People Logic
December 2022 1,000 Lamps Logic, Algebra
December 2022 FORTY + FIFTY + ZERO + ZERO = NINETY Logic, Algebra

2023

  Date   Name of Problem of the Month Math Needed
January 2023 The New Year Challenge Logic, Algebra
January 2023 Minimum Wage Arithmetic
January 2023 MYTH: MATH IS HARD Arithmetic, Logic
January 2023 Bicycle Helmets Probability
           
February 2023 Mean, Median, Mode Arithmetic, Logic, Statistics
February 2023 Four Cars Algebra, Logic
February 2023 Book Problem Algebra, Logic
February 2023 The number 201 Algebra, Logic
           
March 2023 Pie Eaters Algebra
March 2023 Green Eggs and Ham Arithmetic, Logic
March 2023 Number Cross Sums Arithmetic, Logic
March 2023 Mathematical Wackie Wordies Logic
           
April 2023 Return of the Island People Logic
April 2023 Pen Problem Algebra
April 2023 Three zeros Logic, Arithmetic
April 2023 How Many Oranges? Logic, Algebra
           
May 2023 World Cup Soccer Logic
May 2023 Digit Problem Algebra, Logic
May 2023 Locker Problem Algebra, Logic
May 2023 47 Counters Algebra, Logic
           
June 2023 How far did Jonah drive? Algebra
June 2023 31 Students Logic
June 2023 Window Problem Arithmetic
June 2023 Box in a sphere Geometry
           
July 2023 Book Problem Algebra
July 2023 Ordered Triples Problem Algebra
July 2023 Circle Problem Geometry
July 2023 Locker Problem Algebra, Logic
           
August 2023 Hidden Math Words Logic
August 2023 Painted Cube Problem Geometry
August 2023 Magic Square Algebra
August 2023 Whose sum is correct? Algebra
           
September 2023 Daffy Definitions Logic
September 2023 Trapezoidal Problem Geometry
September 2023 Mr. P Problem Logic
September 2023 The Girard And de Marco Families Logic
           
October 2023 Odd Letter Out Logic
October 2023 Hex Path Logic
October 2023 Mailbox Numbers Logic
October 2023 How Old are the Daughters? Logic
           
November 2023 Bo, Jo, Mo, and Flo Algebra
November 2023 Weight Loss Problem Algebra
November 2023 What's My Number? Logic
November 2023 Company Gift Algebra
           
December 2023 Christmas Phobias Logic
December 2023 Christmas Wackie Wordies Logic
December 2023 Sum More Christmas Trees Arithmetic, Logic
December 2023 Who is leading Santa's Sleigh? Logic
           

2024

  Date   Name of Problem of the Month Math Needed
January 2024 The New Year Challenge Logic, Algebra
January 2024 Mid Loop Logic
January 2024 2004 Super Bowl Logic, Arithmetic
January 2024 Golf with Tiger Woods Algebra II
           
February 2024 Chess Tournament Logic, Probability
February 2024 Washington Monument Baseball Problem Calculus
February 2024 Ten Mile Hike Algebra II
February 2024 Lucky Numbers Logic
           
March 2024 Pi Problem Logic
March 2024 Circle Problem Algebra
March 2024 Logarithm Problem Algebra II
March 2024 Puzzle Shop Puzzle Logic
           
April 2024 Six Coins, Three Ways Logic, Arithmetic
April 2024 4 x 4 Square Logic
April 2024 How Far Can You See? Geometry
April 2024 Who Am I? Logic, Arithmetic
           
May 2024 Can you break the code? Logic, Arithmetic
May 2024 Center of a Cube Geometry
May 2024 The Fantastic Formula Algebra
May 2024 Horses and Chickens Algebra or logic
           
June 2024 Colorado Temperature Change Algebra
June 2024 Five Numbers Algebra
June 2024 From American Somoa to Fiji Logic
June 2024 Knights and Liars Logic
           
July 2024 SUM Things to ponder Logic, Arithmetic
July 2024 Pretzel Problem Logic, Algebra
July 2024 Tetrahedron Problem Geometry, Algebra
July 2024 Where do the Magicians Rank? Logic
           
August 2024 Special Birthday Card Algebra
August 2024 Which Way to Jubilee? Logic
August 2024 Prime Time Soccer Logic, Arithmetic
August 2024 Boxes of Red and Blue Balls Logic, Arithmetic
           
September 2024 Cleaning up the Yard Algebra, Logic
September 2024 Midnight and Mr. P Algebra, Logic
September 2024 Soccer Standings Logic
September 2024 Tom, Dick, and Harry Logic
           
October 2024 Math Path Arithmetic, Logic
October 2024 How Tall is That? Arithmetic
October 2024 Olympic Games Logic
October 2024 Another Chicken Nuggets Problem Logic, Arithmetic
           
November 2024 Dave and Carol Logic
November 2024 Urim and Thummim Probability
November 2024 No Hunting! Geometry
November 2024 Sequence Problem Algebra
           
December 2024 Sum Christmas Trees Logic, Algebra
December 2024 Regions in a Circle Geometry
December 2024 The Devil and Daniel Webster Arithmetic
December 2024 The Diamond Tree Challenge Logic