Category Archives: Spatial reasoning

Billy’s Big Christmas Party

Billy was delighted to have gained entry to the Big Christmas Party in the neighbouring village. There were stalls and booths littered throughout the hall.

1) The apple pie stall**/*****
The first stall he walked to showed delicious steaming hot pieces of apple pie on display. Several other kids had gathered in front of it.
A sign read:
4 and 7 give 33
3 and 2 give 5
8 and 5 give 39
A middle aged lady behind the stall held up two numbers: 6 and 3.
“This woman must be the wife of the math teacher,” he whispered to his neighbour.
The lady must have overheard him, because she laughed:
“Young man, I am the math teacher.”
But she was quickly satisfied when Billy quickly figured out the correct answer, collected his piece of apple pie and walked to the second stall.

You can check your solution here

2) The hot chestnuts stall****/*****
The second stall displayed dishes of chestnuts filled with had chestnuts. A man was roasting the chestnuts on a small coal fire and serving them with several sauces.
A sign displayed some calculations:
11 + 11 = 8
12 + 59 = 18
18 + 47 = 16
23 + 39 = 16
He held up two numbers for the children in front of his table: 22 and 45.
Slightly softer than the previous time, Billy whispered to the girl besides him:
“Do they have two math teachers here?”
The girl looked at him saying:
“Did you ask if we have two math teachers here?”
The man heard it and laughed: “No, I’m the Arts teacher.”
Billy quickly grasped the problem and found the sum of 22 and 45.

You can check your solution here

3) The mince pies****/*****
The third stall displayed a lovely looking plate with mince pies.
A piece of cardboard listed:
5 and 6 give 6
3 nd 7 give 7
7 and 8 give 8
She held up two cards showing 4 and 12. “What number do they give?” she asked. “I’ll tell you in advance the answer is not 12.”
To prevent him from asking, the girl besides him told him:
“No, she doesnt teach math. She teaches English.”

You can check your solution here

New puzzles are published at least twice a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars.

Chaos checks

In september last year, I wrote about ‘Vinken’ or ‘Checks’, a Sanders puzzles publication. My main comment was that it was a nice puzzle variation, but that the puzzles were slightly too easy. Sanders puzzels corrected this in later issues.

I did come up wit a slight variation, though the puzzle I designed didn’t make the puzzle difficult enough for my tast. Anyway, I’d like to present this variation to the world.

The rules are simple:
– every row and column, and every 9 sized area, contains 3 checks.
– the checkmarks are never adjacent horizontally or vertically. They may be adjacent diagonally.
– some checkmarks have been pre-filled, as well as some empty squares.

Here are three examples.
puzzle 1*
As you can see some checks and some empty positions have been given. You hve to derive the position of the remaining checks.
Vinkies-chaos 9x9 nr1 exercise

puzzle 2*
This time only some empty positions have been given as clues.
Vinkies-chaos 9x9 nr2 exercise

puzzle 3**
Again only some empty positions have been given as clues.
Vinkies-chaos 9x9 nr3 exercise

You can check your solutions here

A new puzzle is published every Friday.


This puzzle type has nothing to do with the game “letter boggle”.

As usual, the rules are simple:
– fill in the entire alphabet, using every letter exactly once;
– consecutive letters are adjacent horizontally, vertically or diagonally;
– a letter in the border means that the letter appears in the indicated diagonal, row or column;

In the following puzzle, some letters are given to help you start:
1) Letterboggle*
Letter boggle 2013-12-30 nr 1 - exercise

I found this type of puzzle in “PUZZEL”, a year-end addendum to the newspaper reformatorisch dagblad. It had 2 puzzles of this type, copyrighted M. Balmaekers, though Mr. Balmaekers used a 5×5 square and dismissed the letter Q. I intend to have more puzzles like this in one of the upcoming e-books.

I would like to encourage you to solve this puzzle on your own. It will increase your self confidence, while looking up the answer will lower your self esteenm.>When you have solved this puzzle, you can check your solution here

You are welcome to remark on the puzzles, and I love it when you comment variations, state if they are too easy or too difficult, or simply your solution times. Please do not state the solutions – it spoils the fun for others. I usually make the solution available after one or two weeks through a link.