Author Archives: 7puzzle

The Main Challenge In all four groups below, it is possible to make 24 by using the four numbers once each, with + – × ÷ available. Can you show how to achieve the target number of 24 in each case?    3  … Continue reading →

The Main Challenge By allocating each letter of the English alphabet a numerical value as follows, A=1 B=2 C=3 . . . Z=26, the value of the word CAT would be 24, calculated by doing 3+1+20. Following this rule, what … Continue reading →

The Main Challenge Firstly, allocate each letter of the English alphabet a numerical value as follows, A=1 B=2 C=3 . . . Z=26.  If the value of the word DOG is 26 by calculating 4+15+7, for example, which TWO of … Continue reading →

The Main Challenge If you add 1+4, then to that answer add 9, then keep on adding consecutive square numbers to the previous total, what is the first answer you reach that is greater than 200? (Hint: Square numbers are … Continue reading →

The Main Challenge You’ve rolled the numbers 2, 3 and 4 with your three dice.  Using these once each, with + – × ÷ available, what is the lowest positive whole number it is NOT possible to make? Visit Roll3Dice.com for further details of similar challenges. … Continue reading →

The Main Challenge Try the following 20 steps in your head.  Start with the number 12, then: ÷2   –1   ×5   –5   ×3   –6   ÷2   –3   ÷3   ×2 –10   +6   ×3   –6   ÷2   +3   ÷3   +2   –4   ×6   =   ? What … Continue reading →

The Main Challenge In this addition-only Mathelona-style puzzle, place the following 12 numbers into the 12 gaps so that all four lines work out: 1    1    2    3    4    4    5    5    6 … Continue reading →

The Main Challenge Using the three numbers 3, 6 and 9 just once each, with + – × ÷ available, THREE of the following target numbers are not possible to make: 3   6   9   12   15   18   21   24   27   30   33   36 … Continue reading →

The Main Challenge Apart from 9+5+1, find the SEVEN other ways you can make 15 when combining and adding together three unique digits from 1-9. The 7puzzle Challenge The playing board of the 7puzzle game is a 7-by-7 grid containing 49 different … Continue reading →

The Main Challenge Your task is to arrive at the target number of 20 by adding together five numbers.  You are limited to using digits 1 to 5 but these can be used any number of times in each calculation. One … Continue reading →