Explanation:
By using exactly four 4s it is possible to write a few numbers: at least from 0 - 30.
=> For example, using exactly four 4s, we can write 1 as follows
1 = 44 / 44
The right hand side of the above equation has exactly four 4s and solving it will give 1.
=>Using exactly four 4s, we can write 2 as follows;
2 = (4/4) + (4/4)
Also, there are exactly four 4s in the right hand side of the above equation and solving it gives 2
=> Using exactly four 4s, we can also write 6 as follows;
6 = 4 x .4 + 4.4
The above equation also contains exactly four 4s which will give 6 when solved. i.e
(4 x .4) + 4.4 = (4 x 0.4) + 4.4 = 6
The expressions for numbers 1 through 10 using exactly four 4s have been tabulated and shown in the image attached to this response.