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Homemost significant digit

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# most significant digit

The most significant digit of a number $n$ written in a given positional base $b$ is the digit in the most significant place value, and has to be in the range $-1<d_{k}<b$. In the case of an integer, the most significant digit is the $b^{k}$’s place value, where $k$ is the total number of digits, or $k=\lfloor log_{{b}}n\rfloor$.

In an array of digits $k$ long meant for mathematical manipulation, it might be convenient to index the least significant digit with index 1 or 0, and the more significant digits with larger integers. (This enables the calculation of the value of a given digit as $d_{i}b^{i}$ rather than $d_{i}b^{{k-i}}$.) For an array of digits meant for text string manipulation, however, the most significant digit might be placed at position 0 or 1 (for example, by Mathematica’s IntegerDigits function).

In binary, the most significant digit is often called the most significant bit.

## Mathematics Subject Classification

11A63*no label found*

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