Th e Main Challenge
Each of the nine letters, A-I, in the two sections below has a subtraction calculation attached to it. Which is the only letter that has the same answer in both sections?
- Section 1
C:24–13 G:14–6 D:20–10 E:15–7 I:14–9 F:18–11 B:9–2 A:17–5 H:25–12
- Section 2
I:16–3 A:15–1 H:20–8 C:19–9 G:12–4 E:11–5 F:21–6 D:14–7 B:27–18
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 & 7th rows contain the following fourteen numbers:
3 4 10 11 24 27 30 32 35 44 54 60 70 77
What is the difference between the highest and lowest 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 just TWO ways of making 80 when using Lagrange’s Theorem. Can you find them both?
The Mathematically Possible Challenge
Using 2, 3 and 11 once each, with + – × ÷ available, which FOUR numbers is it possible to make from the list below?
5 10 15 20 25 30 35 40 45 50
#5TimesTable
The Target Challenge
Can you arrive at 80 by inserting 4, 5, 8 and 10 into the gaps on each line?
- ◯×◯+◯×◯ = 80
- ◯×◯×(◯–◯) = 80
- ◯×◯×(◯–◯)² = 80
- (◯–◯)×(◯–◯)² = 80
- ◯³+◯×◯÷◯ = 80
Answers can be found here.
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