Answer:
I am owned by every man, though my length differs. Their wives use me after getting married. What am I?
Four fingers and a thumb, yet flesh and blood I have none. What am I?
Adored by few, feared and hated by many. Mistress of the entire universal reason, master in the art of numbers. Some may have solved many of my mysteries, but there are still many of them to find. What am I?
I start new then become old. Start clean but become dirty. I usually start big then become little. What am I?
I look like a tiny trombone
Runs over fields and woods all day. Under the bed at night sits not alone, With long tongue hanging out, Resting at your feet until we go for a walk