#RecreationalMath
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karencampe.bsky.social
November is here, and so is the next Calendar of problems!
Enjoy these with your students or for yourself, share your thinking here or on the post.
#MTBoS #iTeachMath #T3Learns #MathSky #RecreationalMath #MathsToday
karendcampe.wordpress.com/2025/11/01/n...
November Calendar Problems
Wow, November has blown in with some wild weather, but at least we can get an extra hour of sleep tonight as we “fall back” to standard time. It’s a busy month at school, as the f…
karendcampe.wordpress.com
November 1, 2025 at 12:19 PM
stevemaths.bsky.social
Better late than never, the #OCRMathsPuzzle for this week.

What is the value of a, b, c, d and e?

For some of you - I hope the half term break was relaxing. For the rest of you - have a good break next week.

#UKMathsChat #RecreationalMath #Algebra #Statistics
Five integers (a, b, c, d and e) have a mean of 0, a median of 1 and a range of 9. The squares of these five integers (a^2, b^2, c^2, d^2 and e^2) have a mean of 10, a median of 4 and a range of 24. What is the value of a, b, c, d and e.
October 24, 2025 at 8:35 PM
stevemaths.bsky.social
Here's our #OCRMathsPuzzle to end this week. 🙂

The vertices of a square just touch four edges of a regular octagon, as below.
The area of the square is 32 cm^2.

Work out the area of the regular octagon.

#MathsToday #UKMathsChat #RecreationalMath #geometry #area
Image describes the geometric problem. The vertices of a square just touch four edges of a regular octagon. The area of the square is 32 cm squared. Work out the area of the regular octagon.
October 10, 2025 at 2:03 PM
karencampe.bsky.social
Here's the September #ProblemSolving calendar...
karendcampe.wordpress.com/2025/09/01/s...

#MTBoS #iTeachMath #MathsToday #MathSky #RecreationalMath
September Calendar Problems
September is here, and so is the school year for my US friends. Start a habit of doing some problem solving in your math classes this year! Here is the 1990 Calendar of Problems from 35 years ago f…
karendcampe.wordpress.com
September 28, 2025 at 1:39 PM
stevemaths.bsky.social
We have our final festive #OCRMathspuzzle of the year below for you! ❄️

Replace each snowflake in the boxes below with one of the digits from 1 to 9, so that each Christmas wreath contains the sum of the digits in its four adjacent boxes.

#maths #puzzle #resource #RecreationalMath #UKMathsChat
9 snowflakes arranged in a 3 by 3 square grid. Replace each snowflakes in the boxes below with one of the digits from 1 to 9, so that each Christmas wreath contains the sum of the digits in its four adjacent boxes. The christmas wreath values, clockwise from top left are 20, 25, 25, 20.
December 20, 2024 at 10:26 AM
karencampe.bsky.social
Solutions for the March Calendar of Problems are posted!
karendcampe.wordpress.com/2025/03/01/m...
Sorry, I'm a day behind, but the April calendar will be up by tomorrow (no fooling!)
#ProblemSolving #MathsToday #RecreationalMath #iTeachMath #MTBoS #T3Learns #MathSky
March Calendar Problems
Wow it is March, and spring is on the way! March is among my favorite months, since it has its own math holiday (Pi Day*). But don’t limit your recreational math to 3-14; you can have math pr…
karendcampe.wordpress.com
April 1, 2025 at 12:30 PM
kevinlschwartz.bsky.social
Integer 2-3-plexity!

2; 3; 2; 3; ... +; x; & [].

Steps to reach k?

Conjectures:

Can't reach 1; 3; 4; 9.

Can reach any >9.

Any integer 2-3 plexity >9, is < integer complexity. Log?
Integer complexity of 36 = 10; 2-3 plexity = 4.

#NumberTheory #Mathematics #RecreationalMath #IntegerComplexity
June 25, 2025 at 2:37 PM
duanehabecker.com
A lovely #RecreationalMath problem for your day.

#iTeachMath #MathSky
A semicircle is drawn. There is a rectangle who is lower right corner is at the right side of the semicircle. The top of the rectangle is tangent to the top of the semicircle. Essentially, the height of the rectangle is the radius of the semicircle. A line is drawn from the lower right corner of the rectangle to where the rectangle intersect with the semicircle. This intersection is somewhere along the left side of the rectangle. We are supposed to find the area of the rectangle.
October 8, 2025 at 3:16 PM
stevemaths.bsky.social
For #MathsToday, here is this week's #OCRMathsPuzzle!

Which diagram has the greater fraction of its area shaded?

Have a great weekend.

#UKMathsChat #RecreationalMath #Geometry #Area #Fractions #IrrationalNumbers
Diagram A has a white circle inside a shaded square. Diagram B is a white square inside a shaded circle. In both diagrams, the inner shape just touches the perimeter of the outer shape. Which diagram has the greater fraction of its area shaded?
October 17, 2025 at 11:23 AM
duanehabecker.com
#RecreationalMath
Source: x.com/mehrdadbas7233...
December 28, 2023 at 8:30 PM
duanehabecker.com
#RecreationalMath #iTeachMath #MathSky
November 24, 2024 at 4:15 PM
donnyd.bsky.social
2023 Finalists | Best Illusion of the Year Contest #RecreationalMath illusionoftheyear.com/cat/top-10-f...
2023 Finalists | Best Illusion of the Year Contest
illusionoftheyear.com
August 3, 2024 at 11:28 PM
duanehabecker.com
Have you ever heard of Pick’s Theorem? Some folk call it Pick’s Formula. It is my favorite mathematical hidden gem.

Whatever you call it, here is my blog post for how you can discover the formula.
#RecreationalMath
#iTeachMath
theothermath.com/ind...
December 29, 2023 at 8:26 PM
duanehabecker.com
#RecreationalMath

Source: x.com/silverbali7/st...
December 29, 2023 at 7:00 PM
karencampe.bsky.social
March Calendar of Problems is posted! Try some #ProblemSolving #RecreationalMath & share thoughts here/on the blog.

Plus BONUS content article: "Math Habits of Mind" Enjoy!
Consider subscribing so never miss a post.
#MTBoS #iTeachMath #MathsToday #MathSky
karendcampe.wordpress.com/2025/03/01/m...
March Calendar Problems
Wow it is March, and spring is on the way! March is among my favorite months, since it has its own math holiday (Pi Day*). But don’t limit your recreational math to 3-14; you can have math pr…
karendcampe.wordpress.com
March 2, 2025 at 1:49 PM
duanehabecker.com
#RecreationalMath #iTeachMath #MathSky
percybuttons3.mathstodon.xyz.ap.brid.gy Suat Ayöz @percybuttons3.mathstodon.xyz.ap.brid.gy · Jun 5
Here's the question for June 5th from the AMS Daily Epsilon of Math Calendar
@DailyEpsilon

#mathstodon #math #maths #mathematics #mathstoday
A non-convex polygon drawn with vertices at points (1.5,4), (2.5,3), (3.5,3), (3,2), (3,0.5), (2,1.5), (0.5,0.5), (0.5,2) and (1.5,2.5). Area of the polygon is x? Question is to calculate x.
June 5, 2025 at 12:41 PM
duanehabecker.com
#RecreationalMath
🧮
A 6x6 square has a red line going from the lower left corner of the square to the midpoint of the top line of the square. The square is partitioned into a triangle on the left and a trapezoid on the right. Inside the trapezoid is inscribed a circle that is tangent to the base of the square, the red line, and the right side of the square. What is the radius of the circle?
November 18, 2024 at 3:01 AM
duanehabecker.com
What fraction is shaded?
#iTeachMath
#RecreationalMath
November 18, 2023 at 5:09 PM
karencampe.bsky.social
The solutions are posted for the December Calendar of Problems! If you've done some #ProblemSolving tell us your favorite solution methods here or in blog comments.
January Calendar coming soon!
#MTBoS #iTeachMath #MathSky #RecreationalMath #MathsToday

karendcampe.wordpress.com/2024/12/01/d...
December Calendar Problems
December is here and my gift to you is the monthly problem solving calendar! Let’s go back 22 years to the December 2002 Calendar of Problems for you and your students to try. I have the last…
karendcampe.wordpress.com
December 29, 2024 at 4:45 PM
duanehabecker.com
#RecreationalMath #iTeachMath #MathSky

This problem has such a delightful answer.
Two posts stand 60 feet apart. Each post has a cable that runs from the top of one post to the base of the other post. 1. How high off the ground do the two cables intersect? 2. How does the height of the intersection change if the two posts are moved closer together?
November 26, 2024 at 3:31 PM
duanehabecker.com
#RecreationalMath #iTeachMath #MathSky
stevemaths.bsky.social Steve Walker @stevemaths.bsky.social · Nov 29
This week's #OCRMathspuzzle is below!

A red segment is constructed next to a green full circle, as seen below.
The area of the green full circle is 48 cm^2.
What is the area of the red segment?

#iteachMath #UKMathsChat #maths #teachers #resources #geometry #circle #triangle
Angle subtended by the red segment is 90 degrees and forms tangent to full green circle
November 30, 2024 at 2:32 AM
duanehabecker.com
#RecreationalMath

Source: x.com/coremath80/sta...

January 1, 2024 at 3:17 AM
duanehabecker.com
I love this problem and wonder how I never came across this problem as a student.
#RecreationalMath
A circle with a line segment that starts at the edge of the circle and extends 24 units through the center, but not all the way to the other side. At the end of the segment is a perpendicular line segment that goes up 12 units to ends at the edge of the circle. The question: what is the radius of the circle?
April 8, 2024 at 10:05 PM
duanehabecker.com
A puzzle for students of all ages.

#RecreationalMath #iTeachMath #MathSky
8 squares are arranged in a figure. 6 of those squares form a 2x3 rectangle. An additional square is placed on each 3-unit side. Place the numbers 1-8 in the squares such that no two consecutive numbers are touching…even diagonally.
April 17, 2025 at 12:03 AM
duanehabecker.com
This was a fun problem to solve.
#RecreationalMath
#iTeachMath

youtu.be/LWnhj-Tum0Q...
Thumbnail to the YouTube video
March 18, 2024 at 2:47 PM