T he Main Challenge
One of our easier Mathelona-style challenges, still utilising the four arithmetic operations. Place the eight digits 1 2 2 3 4 4 5 and 6 into the gaps so both lines work out:
◯ + ◯ = 6 = ◯ × ◯
◯ – ◯ = 2 = ◯ ÷ ◯
If you enjoy this type of number puzzle, click Mathelona for details of our pocket book of challenges.
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 & 4th rows contain the following fourteen numbers:
2 3 9 10 14 15 22 32 35 40 44 54 60 72
What is the difference between the two multiples of 7?
The Lagrange Challenge
Lagrange’s Four-Square Theorem states that every positive integer can be made by adding up to four square numbers.
For example, 7 can be made by 2²+1²+1²+1² (or 4+1+1+1).
There are SIX ways of making 141 when using Lagrange’s Theorem. Can you find them?
The Mathematically Possible Challenge
Using the three digits 2, 6 and 9 once each, with + – × ÷ available, which are the only THREE numbers it is possible to make from the list below?
4 8 12 16 20 24 28 32 36 40
#4TimesTable
The Target Challenge
Can you arrive at 141 by inserting 3, 5, 7 and 12 into the gaps on each line?
- ◯×(◯+◯)–◯ = 141
- (◯×◯+◯)×◯ = 141
- ◯³+◯+◯–◯ = 141
Answers can be found here.
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