What does 2 Chronicles 24:1 mean?

2 Chronicles 24:1 KJV
Joash [was] seven years old when he began to reign, and he reigned forty years in Jerusalem. His mother’s name also [was] Zibiah of Beersheba.

2 Chronicles 24:1 MKJV
Joash [was] seven years old when he began to reign. And he reigned forty years in Jerusalem. His mother’s name also [was] Zibiah of Beer-sheba.

2 Chronicles 24:1 NKJV
Joash [was] seven years old when he became king, and he reigned forty years in Jerusalem. His mother’s name [was] Zibiah of Beersheba.

2 Chronicles 24:1 KJV 2000

Joash was seven years old when he began to reign, and he reigned forty years in Jerusalem. His mother’s name also was Zibiah of Beer-sheba.

Interlinear KJV

Joash /Yow’ash/ was seven /sheba`/ years /shaneh (in pl. only),/ old /ben/ when he began to reign, /malak/ and he reigned /malak/ forty /’arba`iym/ years /shaneh (in pl. only),/ in Jerusalem. /Y@ruwshalaim/ His mother’s /’em/ name /shem/ also was Zibiah /Tsibyah/ of Beersheba. /B@’er Sheba`/

Commentary

Joash was the youngest person to ever become a king as recorded in the Bible. He became a king at the age of seven. And he ruled for forty years in Jerusalem. In all, he was forty-seven years when he died. His life was very eventful. This is a recap of his timeline:

Joash reigns well all the days of Jehoiada, 2Ch 24:1-14. Jehoiada dies; is buried honorably; Joash falls into idolatry; He kills Zechariah the son of Jehoiada, 2Ch 24:15-22. He is spoiled by the Syrians; slain by Zabad and Jehozabad: Amaziah succeeds him, 2Ch 24:23-27.

A great part of his story is explained on 2Ki 12:1-21.