HOW MANY SONS DID ABRAHAM HAVE?

Genesis 16:5 And Hagar bare Abram a son: and Abram called his son's name, which Hagar bare, Ishmael. Genesis 21:3 And Abraham called the name of his son that was born unto him, whom Sarah bare to him, Isaac. Genesis 25:1-2  Then again Abraham took a wife, and her name was Keturah.  And she bare him Zimran, and Jokshan, and Medan, and Midian, and Ishbak, and Shuah. Galatians 4:22 For it is written, that Abraham had two sons, the one (Ishmael) by a bondmaid, the other (Isaac) by a freewoman. (KJV) Hebrews 11:17 By faith Abraham, when he was tried, offered up Isaac: and he that had received the promises offered up his only begotten son, (KJV)

Clearly, Abraham had all eight children listed in Genesis.  In Galatians and Hebrews, the authors are only making reference to specific kids, not saying that these are the only children Abraham had (it would be ridiculous to suppose that any New Testament author would be unfamiliar with the story of Abraham).  The phrase 'only begotten' in Hebrews would appear to be a problem, but the actual word used there actually means 'beloved'.  Not a contradiction.