At 7puzzleblog.com, we produce regular number puzzles for our many followers from all corners of the globe (see our visitors map immediately on the right). Our aim is to help improve basic knowledge and confidence of number & arithmetic in a fun way.
Please enjoy your visit and spread the message about the fabulous number puzzles at 7puzzleblog.com. Have a go at the four challenge below at #37. You can also follow me and my tweets on twitter @7puzzle.
Click this link if you wish to find out more about our main school-based maths workshops, the 7puzzle experience.
Paul Godding, Director of the 7puzzle company
Replace ? with + – x or ÷ so the results of each of the calculations below is 16 when working one step at a time from left to right and using no brackets:
- 6 ? 3 ? 2 = 16
- 2 ? 6 ? 4 ? 8 = 16
- 5 ? 1 ? 3 ? 7 ? 5 = 16
- 3 ? 2 ? 4 ? 2 ? 3 ? 2 = 16
Using the three numbers 2, 3 and 4 just once each, with + – x and ÷ available to you, what is the lowest positive number that it’s NOT mathematically possible to make?
All four arithmetical operations, + – x and ÷, must be used at some point in the following 7-number calculation. Replace each ? so the final answer will be 84 when working from left to right, one step at a time, with no brackets:
1 ? 9 ? 4 ? 8 ? 3 ? 2 ? 1 = 84
Write a + b = c on four separate lines. Your task is to replace all 12 letters with the following 12 numbers so that all four number sentences work out:
1 1 2 3 4 4 5 5 6 8 9 10
Using the three numbers 3, 6 and 9 just once each, with + – x and ÷ available to you, THREE of the following target numbers are NOT possible to make. What is their sum?
3 6 9 12 15 18 21 24 27 30 33 36
To celebrate the development of our brand-new 5puzzle app, here is a 5puzzle-related number challenge to try.
There are six ways to make 10 by adding together five numbers from 1-5. Numbers can be repeated. One way is 5+2+1+1+1, can you find the other FIVE ways?
Try and arrive at the target answer of 24 by using each of the numbers 2 4 4 7 exactly once each, with + – x ÷ available.
Find the first SEVEN whole numbers, above 20, that do not contain a 3, 5 or 7 as part of their number, or are not multiples of 3, 5 or 7. What is the 7th number in your list?
There were 72 golfers taking part in the final day of a tournament. There was an 11-minute gap between each pair’s official starting time from the 1st tee. The first group teed off at 8.25am, what time did the last group tee off?