The Main Challenge Using each of the four numbers 0.8, 0.9, 1.5 and 5 once each, and with the four arithmetical operations + – × ÷ available to use, can you arrive at the target answer of 7? 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 2nd & 3rd rows contain the following fourteen numbers: 8   13   17   25   28   36   42   45   48   55   63  &nbs ..read more

The Main Challenge Carry out the following 15-step number trail – with no calculator! Start with 20, then: +1  ÷3  ×5  –7  +2  ÷6  +4  –1  ×3  ÷4  +4  –5  ×1  +3  ×6  =  ? What is your final answer? 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 2nd & 3rd rows contain the following fourteen numbers: 8   13   17   25   28  ..read more

The 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 ..read more

The Main Challenge If each letter is assigned a value as follows, A=1 B=2 C=3 … Z=26, can you find a 7-letter word in the English language that has the value of 79 when the values of all seven letters are added together? 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    ..read more

The Main Challenge Using the three numbers 5, 5 and 5 once each, with + – × ÷ available, which SEVEN target numbers from 1-30 are mathematically possible to achieve? 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    ..read more

The Main Challenge The two sections below both contain eight letters, A to H.  Each letter has a calculation attached.  Which is the only letter to have the SAME answer in BOTH sections? Section 1 E:8×3   B:30÷2   H:15+3   A:6×6   G:36÷3   C:40–20   F:18+12   D:32–8 Section 2 G:10+6   F:6×5   C:9×4   E:40÷2   H:30–18   A:15+9   D:30–12   B:120÷4 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 ..read more

The Main Challenge It is possible to use seven 4’s (4 4 4 4 4 4 and 4) once each, together with the four operations + – × ÷, to make all the different target numbers 1, 2, 3 and 4. For instance, one way of arriving at the number 1 is: 4 – 4÷4 – 4÷4 – 4÷4 = 1 Can you show how to make the next three target numbers 2, 3 and 4? 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&n ..read more

The Main Challenge Start with the number 13, then follow these ten arithmetic steps: –2   +5   ÷2   ×5   –4   ÷9   +1   ×5   –1   ÷4   =   ? What is your final answer? 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 1st & 6th rows contain the following fourteen numbers: 2   5   9   12   14   15   18  ..read more

The Main Challenge Can you arrive at the target answer of 24 by using the digits 2, 9, 13 and 13 exactly once each and with + – × ÷ available? 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 1st & 6th rows contain the following fourteen numbers: 2   5   9   12   14   15   18   20   22   33   40   49   56   72 Which three numbers, when ..read more

The Main Challenge As well as 9+4+1, there are SEVEN other ways of making 14 when adding together three unique digits from 1-9.  List these seven combinations. 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 1st & 6th rows contain the following fourteen numbers: 2   5   9   12   14   15   18   20   22   33   40   49   56   7 ..read more