The Main Challenge
Your starting number is 18 and your task is to arrive at the same final answer. There are ten arithmetical steps from beginning to end, each one involving a whole number, but the 9th (and penultimate) step is missing! What must it be?
÷2 +3 –8 ×6 +4 –3 ÷5 ×2 ? ×2 = 18
The 7puzzle Challenge
The playing board of the 7puzzle game is a 7-by-7 grid of 49 different numbers, ranging from 2 up to 84.
The 4th & 6th rows contain the following fourteen numbers:
3 5 10 12 18 20 32 33 35 44 49 54 56 60
What is the difference between the lowest and highest multiples of 4?
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 THREE ways of making 59 when using Lagrange’s Theorem. Can you find them?
The Mathematically Possible Challenge
Using 1, 6 and 7 once each, with + – × ÷ available, which FOUR numbers is it possible to make from the list below?
6 12 18 24 30 36 42 48 54 60
#6TimesTable
The Target Challenge
Can you arrive at 59 by inserting 4, 5, 6 and 10 into the gaps on each line?
- ◯×◯+◯–◯ = 59
- ◯²+◯×◯+◯ = 59
- (◯+◯)×◯–◯ = 59
Answers can be found here.
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