The Bourne shell had no arithmetic built in
But there was an expr command (in C) that did arithmetic:
% expr 5 + 4 9
Need formatted output like C's printf?
No problem, someone eventually wrote a printf command
% printf "<%-6s> <%3d> <\$%12.2f>\n" foo 8 12.346 <foo > < 8> <$ 12.35>
