Four Fours

Four fours is a maths puzzle to find the simplest mathematical expression for every integer from 0 onwards. The rules are simple;

  • You can only use the operators; +, -, x, (brackets) , x² square and ! factorial
  • You can only use the number four
  • Each expression must have four fours

Anyway, having some spare time I decided to have an attempt at 0 - 20;

Number Answer
0 (4 + 4)  - (4 + 4)
1 (4 + 4) / (4 + 4)
2 (4 / 4) + (4 / 4)
3 ( (4 + 4) + 4) / 4
4 ( (4 - 4) * 4) + 4
5 ( (4 * 4) + 4) / 4
6 ( (4 + 4) / 4) + 4
7 (4 + 4) - (4 / 4)
8 (4 - 4) + (4 + 4)
9 (4 / 4) + (4 + 4)
10 44 / 4.4
11 (4 / .4) + (4 / 4)
12 4 x (4 - (4 / 4))
13 (4!) - (44 / 4)
14 4 + 4 + 4 + ?4
15 (44 / 4) + 4
16 (4 + 4) + (4 + 4)
17 (4 / 4) + (4 x 4)
18 (4 x 4) + 4 - ?4
19 4! - 4 - (4 / 4)
20 4 x (4 / 4 + 4)

I'm sure there are many different ways you can achieve each integer, but these are the simplest ones I could think of at the time.

 

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