Which digit is referred to as the least significant digit?

The least significant digit is defined as the digit that represents the smallest value in a number and is located at the farthest right position in that number. This digit carries the least weight in terms of place value, meaning that any changes to it affect the overall value of the number the least. For example, in the number 345, the '5' is the least significant digit, as it represents only five units, while the digits to its left (3 and 4) represent tens and hundreds, respectively, and thus hold greater significance when determining the total value of the number.

The correct understanding of the least significant digit is crucial, particularly in contexts involving arithmetic operations, binary representations, or systems that rely on numerical significance, such as computing or data encoding. This focus on the rightmost position aligns with how positional number systems are structured, where the significance of digits decreases as you move to the right.