Author Archives: 7puzzle

The Main Challenge Try the following challenge from my number puzzle pocket book.  Further details can be found by clicking on Mathelona. Your task is to make all three lines work out arithmetically by correctly placing the 12 digits 0 … Continue reading →

The Main Challenge You’ve rolled the numbers 1, 3 and 3 with three dice.  Using these once each, with + – × ÷ available, find the TWO target numbers from 1-10 that it is NOT possible to make. The 7puzzle Challenge … Continue reading →

The Main Challenge Group the following numbers into three lots of three so the products of each of the triples are the same. What is this product? 3     4     5     6     7     8     28  … Continue reading →

The Main Challenge The ten letters, A-J, in the following two sections each contains a calculation.  Which is the only letter that has the same answer in both sections? Section 1 E:6÷6   I:5+1   G:3+2   A:10–2   J:4+3   C:5×1 … Continue reading →

The Main Challenge Read the following facts:  I am a 2-digit number,  both my digits are odd,  the sum of both digits is less than 10,  my 1st digit is smaller than my 2nd digit, and  I am a multiple of 3. … Continue reading →

The Main Challenge From all the odd numbers in the range 1-23 inclusive, eliminate all prime numbers and multiples of 3. Which is the only number that remains? The 7puzzle Challenge The playing board of the 7puzzle game is a 7-by-7 grid containing … Continue reading →

The Main Challenge What is the sum of the first SEVEN 2-digit even numbers? The 7puzzle Challenge The playing board of the 7puzzle game is a 7-by-7 grid containing 49 different numbers, ranging from 2 up to 84. The 3rd & 4th rows of the … Continue reading →

The Main Challenge From the list of ten numbers below, find FOUR combinations that total 50, where each combination must contain three different numbers. The numbers are allowed to appear in more than one combination: 7     9     10  … Continue reading →

The Main Challenge By using the four numbers 0.5, 2, 2 and 2 exactly once each, can you arrive at the target answer of 7 with the four arithmetical operations + – × ÷ available to use? The 7puzzle Challenge The playing board of the 7puzzle … Continue reading →

The Main Challenge By using the numbers 4, 5, 7 and 8 exactly once each, and with the four arithmetical operations + – × ÷ available, can you arrive at the target answer of 12 in two different ways? The 7puzzle Challenge The playing board of the … Continue reading →