Power-of-ten digit-block formatting
= Power-of-ten digit-block formatting
When the <radix> is $10^k$, print the highest nonzero normalized digit without leading zeros, then every lower digit as exactly $k$ decimal characters. Internal zero blocks must be retained. With base $1000$, the low-first digits $[4,0,12]$ print as `12` followed by `000` followed by `004`, giving `12000004`. An all-zero representation prints a single zero, independent of its allocated length.