It is said that two cubes with twelve digits on their faces are enough to
produce any date of year from them. Can you discover how the digits should
be placed on the cubes?
Put all the eleven pieces into the 5x5 board so that each row, column, and
main diagonal (both diagonals are highlighted) contains different digits,
1 through 5. No piece is rotated or flipped, and no pieces overlap each
other.
With three straight lines divide the circle into several regions with
equal sums of their numbers. Lines should begin and end on the circle’s
periphery. They may cross each other, but not the numbers. No empty
regions are allowed.
This is a puzzling number tree in which when you already think the
solution is in your pocket you suddenly realize it slipped out because
of a "tiny digital typo". Don't believe? Just give it a try!
Some multiplications can be done in an unusual
way – by moving a digit from one position to another. This challenge
is about the multiplication and... a proper number which such a
multiplication should be applied to.
Nine digits are arranged into two groups of two numbers each. When the
numbers are multiplied in each group the resulting product is the same.
What is the biggest amount which can be created in such groups?
We can arrange four 5's to produce one hundred quite easily, using some
arithmetical signs. The question is how easy it is to arrange four 7's to
obtain the same result?
This is a 3x3 square grid where the rows are the most important. Nine
different digits to be arranged into three numbers observing a special
rule. Take a look at it to see the rule...
A five-pointed star is made of circular spots held together by wire. Fill
in the circles with the correct numbers of stones from 1 through 15
observing some additional rules.
Just write a set of numbers in the circles so that any three of them lying
on a straight line always add up to the same total. Is there any algorithm
to find the proper solution?
A set of four dice, though not marked with spots in the ordinary way, but
with digits. When put together a plenty of different four-figure numbers
can be formed. How many? And what they all would add up to?
Three cubes with three numbers on them should be arranged to create a
number divisible by 7. But is there a way to arrange the cubes in order to
get the proper number?
How many darts will you need to toss and which rings with numbers will you
need to target in order to score exactly 100? Before scoring this number
you can try to score the 50 first.
When 2 is multiplied by 2 it produces the same result as when 2 is added
to 2. It is 4 in both cases. Can you think of another pair of numbers with
the same arithmetical feature?
Digits 1 through 9 stand in a row in ascending order. Just insert a number
of pluses and minuses between them and get 100. And what about the
descending order?
The six numbers from 1 to 6 have to be placed along the sides of a
triangle so that to create some magic sum along each of its sides. What
magic sums can be there?
A sequel to
The "Twenty-Six" Puzzle. Numbers 1 through 12 and the magic
sum of 26 remain, but the seven areas have changed. Will it be harder than
the prequel?
It is quite easy to get 24 from an 8 and a 3 - just multiply them
together. But discover how incredibly hard this task can be when you have
two 8s and two 3s.
It's a kind of magic square, and you have to place twelve different
numbers all around it so that seven regions with the magic sum of twenty
six appear.
Solving this puzzle you can circle with a feeling that you're one step
before your goal or... one step behind. Is there any kind of joke to get
exactly on it?
A true classic gem passed through the time. Despite the fact you need just
simple arithmetic skills to get to the solution, it will make you be
thinking slightly out of the box.
