See the working of some common math functions like sqrt, pow, log and log10
Rounding and related functions like ceil, floor, round, rint, trunc etc. in c++
Using the specially created modulus function fmod() for fractions like float and double data type.
Using the modf() function to separate the integer and fraction part of fractional value.
Using toupper() and tolower() function for character level conversion in its ascii integer form.
Check for character grouping in the ascii 7 bit range of control character, digit, punctuation, alphabet, alphanumeric, lowercase, uppercase, printable, graphical, white space etc.
The functions which are frequently used in C, getchar() and putchar() provide a feature of character level console input and output facility.
Using get() and put functions of I/O stream methods like cin and cout.