.4 is the smallest since 4/10 is smaller than 4/9 and is only worth 400/1000.
4/9 is a repeater .444.... with the fours continuing forever. If we just go out 3 places from the decimal we get .444 which is 444/1000 and is the second number. Because the 4's continue to go on forever this makes it larger than 444/1000
So the correct order least to greatest is .4 < 444/1000< 4/9
