just formalized my solution to the problem any thoughts?

Magic Square : Sum of rows = Sum of columns = Sum of diagonals

Find the missing values ?

I've added a new test to my free online battery: Tug of War. You see how a few tug-of-war matches ended and rank the figures from strongest to weakest. It's meant as a quantitative reasoning task, and I want to see how it compares with the Weights test (figure weights).

About 10 minutes, 45 s per item. If you've already done Weights, that helps the most.

www.jaroslavtocik.cz/reasoning/

Percentiles will show up once enough people have taken it. Feedback on unclear or broken items is welcome.

FREE LESSON in the Mathematics Library at Golden State Lessons

The first in a series of 5 Lessons on the Story of Numbers. Please consider purchasing Lesson 2 when it becomes available.

PUZZLE RULES
Use each die exactly once, in any order.
Reach the target using only +, −, ×, ÷.
Parentheses are allowed.
Operations can be repeated or skipped. You don’t have to use all four.
All intermediate results must be positive whole numbers (no zero, negatives, or decimals).
Exact division only.
No concatenation (e.g., 2 and 3 cannot become 23).
No exponents or other operations.

How many solutions can you find?

Please use spoiler tags for solutions:
>!your solution here!<

tafol.pythonanywhere.com

How to play

Naoki Inaba invented Tetra Barrier using tetrominoes. Here we use the full set of twelve pentominoes, and that changes the problem considerably: it is not enough to place the pieces; you must place them so that they do not touch and, at the same time, enclose each X in its own region.

The board. An 11×11 grid with twenty or twenty-one X marks. The twelve pieces cover sixty squares; the other sixty-one remain empty. Those empty squares form regions bounded by the pieces and the edge of the board.

The rules. Place all twelve pentominoes —F, I, L, N, P, T, U, V, W, X, Y and Z— using each one exactly once. They may be rotated and reflected, but they may not touch along their edges; touching at corners is allowed. In addition, each empty region must contain exactly one X.

The key point is what counts as a region: not just any area, but a closed group of edge-adjacent squares. The boundaries are not drawn in advance: the pieces form them, sometimes with help from the edge of the board. If two X marks are connected without crossing a piece, they belong to the same region and the placement is not valid.

The goal. Each puzzle has a unique solution. A hint to get started: look for X marks that are very close together. Separating them forces you to put some wood in the narrow space between them, and that often determines the first piece.

tafol.pythonanywhere.com

Hi everyone!

We are the SquareStepMath Team, and we're currently developing a new online math course designed to help children build a strong foundation in arithmetic and become more confident in math.

Our approach focuses on teaching children how to solve calculations step by step, using clear written methods. The course covers whole numbers, decimals, and fractions, helping children develop essential skills for more advanced math topics later on.

We're currently looking for a small group of children to participate in a free 4-week pilot program. Since we're still developing the course, we'd love to hear from parents and children about what works well and what we could improve.

What does the pilot involve?

• 1 day of instruction per week through pre-recorded videos.

• 5 days of practice per week, with approximately 20 problems per day.

• A total of 4 weeks of instruction and practice.

• Completely free participation. In return, we simply ask for your honest feedback!

Children can start whenever it suits them.

What kind of math problems will children learn to solve?

Here are a few examples of the types of calculations covered in the course:

1. 47,586 + 8,947 + 675 =

2. 70,000 - 38,647 =

3. 4,578 × 36 =

4. 7,094 × 58 =

5. 127.46 + 38.795 =

6. 300 - 147.68 =

7. 83.2 × 4.75 =

8. 2/3 + 3/4 =

9. 5/6 - 1/4 =

10. 2/3 ÷ 3/4 =

Interested in taking part?

You can learn more about us at [SquareStep Math – website link].

If you'd like your child to participate in the pilot, please send us an email at [email protected].

We'd really appreciate your help in testing and improving our course!

Thanks for your time!

Best regards,

The SquareStepMath Team

This post is to announce that there will be a lecture course on General Topology (a.k.a. Point-Set Topology) conducted in Mandelcord (the blue math discord server). Everyone is invited to join: discord.gg/maths.

If any of you were present in the Real Analysis lecture course during the summer, you know what I'm talking about, and you might be pleased to hear that this course will also be run by Pear Category Theorem (the same person).

Why YOU should do topology

Point-set topology is one of the most important subjects that you learn, and mastering topological thinking is as important a milestone as learning to write a proof. This is a good subject to study alongside measure theory, or simply by itself after one has learned analysis or algebra.

Course Structure

The course will primarily follow the flow of the first half of Munkres. The plan is to go through all 8 chapters, spending maybe one to two weeks on each chapter, aiming for an approximately 16 week course. Also the instructor intends to supplement the book with his own intuition on the subject, as well as connections to other subjects that he thinks are of interest and possibly also other topics not covered in the book. Many examples of various pathological properties will be provided. The study of metric spaces and functions on them will be paramount; but where Rudin introduces metric spaces as merely a generalization of Euclidean spaces, we will explore just how pathological these spaces can be, or else what properties they must have.

The instructor also plans to put far more focus on the topics of topological groups and nets than Munkres does. Topological groups, because often in "the real world" we do not care about a topological space by itself, but rather some other more complicated structure given a topology, in order to see what the topology can tell you about the thing itself; topological groups provide a playground to learn that mode of thinking. Nets are also very important; where sequences are of importance in R, they can only tell you so much in general topological spaces, so nets therefore become the natural way to recover theorems about sequences.

Material and References

1. Topology - Munkres

2. Counterexamples in Topology - Steen & Seebach

Timeline

The course starts with the first lecture on 17th November at 9 PM CET (20:00 UTC), with subsequent lectures on Tuesdays and Thursdays. Lectures will be recorded and posted promptly.

Prerequisites/Who can join?

Everyone. It is completely free for anyone who wants to join. Just click the link and join the server: you can find the channel called topology-course in the section called General maths. As for prerequisites, a first course in Real Analysis and Group Theory is sufficent.

Looking forward to see all of you there. Thank you.