438 is an integer and so there is no sensible way of writing it as a fraction or mixed number.
0.0137
4.38 = 438/100 = 419/50
0.0023
Fraction: 438/100 = 219/50 Mixed number: 219/50 = 4 and 19/50
4.38 = 438/100 = 219/50
This can be written as 7 + 8/1000 or in proper fraction form as 7008/10,000 = 7008÷16 /10,000÷16 = 438/625.
0.0123
438 as % rate:= 438 * 100%= 43800%
You could write it as 3504/1000, or simplified to 438/125. As a mixed number, it would be 3 63/125.
438, 876, 1314, 1752, 2190, 2628, 3066 +438 . . .
438-122 = 316