To compare the values you have to look and compare the digit in the first decimal place, the closer the value is to zero, the smaller it is.
For 0.4 and 0.127, the first digits are 4 and 1, as you can see, 4 is greater than 1,
Symbolically 4 > 1
So you can say that 0.4 is greater than 0.127, symbolically: 0.4 > 0.127
Remember
The symbol "<" indicates that the number on the left is less than the number on the right.
The symbol ">" indicates that the number on the left is greater than the number on the right.
And "=" indicates that both values are equal