why do we always round our birthdays down with a floor function. In Joseph Smith History, (in my fifteenth year) he uses a ceiling function.

Also why do we always settle on the precision of a year as adults? I know kids often use half years.

So from now on, when ever anyone asks my age, I am going to use a ceiling function with 5 year precision.

That way, I only will have to "math" twice a decade. Much easier.