You might have seen a pain scale in your doctor's office before. One common type shows a series of numbered cartoon faces moving from 0 (smiling and pain-free) to 10 (weeping in agony.) A doctor would ask a person in pain which face matched up with what they were feeling. They might seem simple.
In our day this might be more than one. For Israelite King Echov, one particular foreign wife, Isabel, was one too many. King David is said to have had eighteen wives and concubines, seven mentioned by name in the OT and the others mentioned in the oral tradition.
In 1 Kings 2:10, 11 we find how long he reigned over Israel: So David slept with his fathers, and was buried in the city of David. And the days that David reigned over Israel were forty years: seven years reigned he in Hebron, and thirty and three years reigned he in Jerusalem.