Rounding is usually done by rounding up values that have a fractional part that is at least 0.5, and rounding down values that have a fractional part of less than 0.5. This means 14.55 is rounded to 15, while 2.3 is rounded to 2.

C/C++ does not have a rounding function. However, rounding can be achieved using the following math (the floor (Links to an external site.) of x plus half):

r o u n d ( x ) = x + 1 2 = 2 x + 1 2

In the process of converting base-10 scientific notation to base-2 scientific notation, it not uncommon that we need to divide numbers by 10, and rounding can be integrated in the division:

r o u n d ( x 10 ) = x 10 + 1 2 = x + 5 10

The nice part is that integer division automatically truncates and for non-negative values, it is the same as taking the floor function.

Compute the difference between the rounded version and the truncated version of 13.57/10.