May 21, 2018:

A new week, and a new beginning, with an easy puzzle on Monday:

The Sunday Puzzle – a Numoku-esque variation – is a light and fun thing to try on the weekend:

The Saturday’s Hard Numoku Puzzle this week has a twist in it. The sum’s aren’t 30 (why should they always be?), and so a few usual tricks won’t work:

The Saturday’s classic puzzle will give a good shake up to your mental faculties on the weekend. All you need to do is try to solve it entirely in the head:

The Weekend Puzzle this week is another four-in-one multi-puzzle variation, and a fairly tough one. Think you can figure it out?

A new puzzle for this Friday. Can be quite easy if you get the trick:

The Thursday’s Numoku Puzzle, although a ‘medium’, leans more towards ‘hard’:

The Thursday’s puzzle too is a bit trickier than the usual ‘medium’ puzzles. Can you think it through?

This week’s AtoZ Puzzle is not too hard, provided you don’t make yourself dizzy looking at it:

The Wednesday’s Puzzle is a good test for your logical thinking as well as factorization skills:

The Tuesday’s Numoku puzzle is an easy one – perfect for the beginners before they advance to the medium or hard versions of this puzzle:

The Tuesday’s regular puzzle is harder than it looks. How will you figure out your first clue (without guesswork or trial-and error!)?

The new week begins with an easy puzzle for Monday:

The smallest number that, when its last digit is moved to the first place, becomes four times its original value is 102,564 (410,256 = 4 x 102,564).

What is the smallest number that, when its last digit is moved to the first place, becomes double its original value?

Can you guess the next number in the series:

5 8 12 18 24 30 36 42 52 60 68 78 84 90 100 … ?

For the Harry Potter fans: You are watching the first Harry Potter movie. Harry has ticket for Platform 9 3/4. There is a column, right in the middle of Platforms 9 and 10, and you see Harry and the other kids running straight into the center of the column to get to Platform 9 3/4.

What is probably wrong with this scene?

Send your solutions by comment, by email to 1to9puzzle@gmail.com, or via tweets tagged to @1to9puzzle.

All these puzzles are logical and can be solved purely by reasoning, without any need for guesswork or trial-and-error. I quite often post the step-by-step reasoning along with the solution on Twitter.

For solutions and for more puzzles follow me on Twitter @1to9puzzle