2050.22 – Four 4’s: 21 – 40


In a previous problem, you found mathematical expressions equal to each of the whole numbers from 1 to 20 using exactly four 4's plus any mathematical symbols you wanted to use. Using the same rules, make the whole numbers 21 - 40.


Solution

21 = 4! – \sqrt 4 – (4 ÷ 4)

22 = 4! – \sqrt 4 + 4 – 4

23 = 4! – \sqrt 4 + (4 ÷ 4)

24 = [(4 x 4) + 4] + 4

25 = 4! + \sqrt 4 – (4 ÷ 4)

26 = 4! + (4 + 4) ÷ 4

27 = 4! + \sqrt 4 + (4 ÷ 4)

28 = 4! + 4 – 4 + 4

29 = 4! + 4 + (4 ÷ 4)

30 = 4! + \sqrt 4 + \sqrt 4 + \sqrt 4 or (4 + 4 + 4) ÷ .4

31 = [(4! + 4) ÷ 4] +4!

32 = 4! + 4 + \sqrt 4 + \sqrt 4 or (4 ÷ .4) + 4! – \sqrt 4

33 = [(4 – .4) ÷ .4] + 4!

34 = 4! + (4 x \sqrt 4) + \sqrt 4

35 = [(4 + .4) ÷ .4] + 4!

36 = 4! + 4 + 4 + 4

37 = [(4! + \sqrt 4) ÷ \sqrt 4] + 4!

38 = 44 – \sqrt 4 – 4

39 = 4! + (4 + \sqrt 4) ÷ .4

40 = 4! + 4! – 4 – 4

Fun Fact: One can find expressions like this for every counting number up to 100 using these functions and tricks How far can youyou get?