Follow the rules and eliminate every number from a given list, except one. So, which one will be the LAST ONE STANDING?
From the even numbers 10 12 14 16 18 20 24 28 30 36 40 42 48 50, eliminate all multiples of 3, 5 and 7. Which is the only number that remains?
Here is another posting of my popular WHO AM I? puzzle. Both teachers and children enjoy this, so here’s another challenge where clues are given to help you find a particular number.
Read the following facts to work out my numerical value today:
- I am a 2-digit prime number above 50
- I am one higher than a multiple of 7
WHO AM I?
Another showing of our CAS puzzle to celebrate the POSSIBLE100 app that has been developed by the Y5 children of Casllwchwr PS in Swansea, which is now available in the AppStore. This number puzzle is similar to the regular POSSIBLE number puzzle, but you can only use addition and subtraction in this case:
Using the numbers 1 2 3 once each, with just + and – available to use, find the only FOUR possible target numbers that can be achieved from 1-9.
The 2013 edition of my 5teaser game, the younger version of 7puzzle, has now been released, so here’s a 5teaser question involving numerical combinations:
Your task is to arrive at the target number of 15 by adding together five numbers. You are limited to using 1-5, but these can be used any number of times in your calculation. Apart from 3+3+3+3+3, can you find ELEVEN other ways of achieving 15?
For further details of the game, please click on the 7puzzle & 5teaser games link.
It’s the weekend and here’s another KENKEN puzzle to try for both old and new fans. Today sees a 6×6 puzzle posted to test your arithmetical skills.
In the following KENKEN grid, every row and column must contain the numbers 1-6 and numbers cannot be repeated. Within each heavily outlined area, or cage, numbers must arrive at the given answer. For instance, a 2-box cage with 3- requires the two numbers to have a difference of 3. A single-box cage simply contains that number:
If you enjoyed this, click on KENKEN to go directly to their site and try some puzzles on-line. As well as this 6×6 challenge, there are many different-sized puzzles available to try.
Another COUNTDOWN-style challenge for you to try. The slight difference from this to the numerical challenges seen on the Channel 4 show in the UK is that all SIX numbers must be used in this particular number puzzle:
Using all six numbers 1 2 2 3 4 and 75 once each, with + – x ÷ available, can you arrive at the target number of 960?
An improved and updated version of the old mathematically possible board game will be released this summer. The numbers used in the possible game calculations will now range from 1-12:
Using the numbers 5 6 12 once each, with + – x ÷ available, list TEN different target numbers that are possible to achieve from 1 to 30 inclusive?
Click on the mathematically possible series of games above at PAUL’s GAMES & PUZZLES to gather more details of the new game.
A number puzzle to test your mental arithmetic, particularly those adding skills involving your knowledge of prime numbers:
If you started with the number 7, and to this starting number kept on adding consecutive prime numbers from the very beginning, what is the first total you would reach that’s greater than 100?
The playing board of the 7puzzle game contains 49 different numbers, the lowest being 2 and the highest 84. There are seven rows on the board, each row consisting of seven numbers.
The 3rd & 4th rows of the board contain the following fourteen numbers:
3 10 13 25 32 35 36 42 44 45 54 60 66 80
From this list:
What is the total when adding together all the multiples of 7
- Add together the prime numbers and square numbers on the list. What do you get?
- List FOUR numbers that total 100
In a similar way to last year, I want to use this blog to wish my older daughter, Georgi, a very happy 19th birthday. To celebrate that, here is a MAKE puzzle to try.
Have a go at solving these three different-sized number problems by using some mental arithmetic, where 19 is the common target. Replace ? with + – x or ÷ so the results of each of the calculations are 19 when working one step at a time from Left to Right (no brackets allowed):
- 3 ? 5 ? 4 = 19
- 2 ? 3 ? 4 ? 5 = 19
- 1 ? 2 ? 3 ? 4 ? 5 = 19