Expressions can contain several operations, as in:

A+B*C

As is customary in mathematics, all multiplications and divisions and remainder operations are performed before additions and subtractions. When handling the foregoing expression, awk performs B*C first and then adds A. The value of:

2+3*4

is therefore 14 (3*4 first, then add 2). If you want a particular operation done first, enclose it in parentheses, as in:

(A+B)*C

When evaluating this expression, awk performs the addition before the multiplication. Therefore:

(2+3)*4

is 20 (2+3 first, then multiply by 4). As an example of this, consider the program:

{ print $4/($3*52) }

$4 is the amount of money a person spent on a hobby in the last year. $3 is the average number of hours a week the person spent on that hobby, so $3*52 is the number of hours in 52 weeks (that is, 1 year). $4/($3*52) is therefore the amount of money that the person spent on the hobby per hour.