Topic summary
Significant digit
Extracted from the Wikipedia article Significant figures.
Among a number's significant digits, the most significant digit is the one with the greatest exponent value (the leftmost significant digit/figure), while the least significant digit is the one with the lowest exponent value (the rightmost significant digit/figure). For example, in the number "123" the "1" is the most significant digit, representing hundreds (10), while the "3" is the least significant digit, representing ones (10).