The Main Challenge
. . . is a tricky question that’s a real mouth-watering prospect for the number puzzle enthusiast.
Using the numbers 1, 2, 3, 4 and 5 once each, with + – × ÷ available, it is possible to make the vast majority of numbers in the range 50-100.
For example, to arrive at 50 and 51, you could do:
- (4+3+2+1)×5 = 50,
- (4×3–2)×5+1 = 51, and so on . . .
Continuing your calculations, what is the LOWEST number in this range that it is NOT possible to make?
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 & 6th columns contain the following fourteen numbers:
4 7 12 15 17 30 35 36 40 49 54 64 80 81
How many square numbers are listed above?
The Factors Challenge
Which of the following numbers are factors of 327?
7 9 11 13 15 17 19 21 None of them
The Mathematically Possible Challenge
Using 5, 6 and 12 once each, with + – × ÷ available, which are the only THREE numbers it is possible to make from the list below?
10 20 30 40 50 60 70 80 90 100
#10TimesTable
The Target Challenge
Can you arrive at 327 by inserting 3, 5, 5, 7 and 7 into the gaps below?
- ((◯+◯)²–◯×◯)×◯ = 327
Answers can be found here.
Click Paul Godding for details of online maths tuition.
