The Main Challenge
From the EVEN numbers in the range 2-40 inclusive, eliminate:
- multiples of 4,
- single-digit numbers,
- numbers which are next to (one away from) a prime number or square number.
Which is the only number that remains?
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 1st & 3rd rows contain the following fourteen numbers:
2 9 13 14 15 22 25 36 40 42 45 66 72 80
What is the product of the two prime numbers?
The Factors Challenge
Which FOUR of the following numbers are factors of 308?
4 5 6 7 8 9 10 11 12 13 14
The Mathematically Possible Challenge
Using 3, 8 and 10 once each, with + – × ÷ available, which is the ONLY number it is possible to make from the list below?
80 81 82 83 84 85 86 87 88 89
#NumbersIn80s
The Target Challenge
Can you arrive at 308 by inserting 2, 4, 6, 8 and 10 into the gaps below?
- (◯²×◯÷◯)–(◯×√◯) = 308
Answers can be found here.
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