The given series of number:
0.42, 0.416, 0.44, 0.409
To arrange from least to greatest is called ascending
For Decimal Values:
Compare the last left digits of the decimal parts of two numbers with the greater left digit at the last will be greater. If the left digits at the last of decimal parts are equal, then compare the next digits and so on.
In all the numbers the first digit after decimal is 4, i.e same in all the numbers
Second digit in all the numbers are 0.42, 0.416, 0.44, 0.409 : 2, 1, 4, 0 respectively
Arrange 2, 1, 4 & 0 in ascending order: 0 < 1 < 2 < 4
So, 0.409 < 0.416 < 0.42 < 0.44
Answer : 0.409 < 0.416 < 0.42 < 0.44