How many of each went into the ark
Only 2 ? 

NIV Genesis 6:19-22
You are to bring into the ark two of all living creatures, male and female, to keep them alive with you. Two of every kind of bird, of every kind of animal and of every kind of creature that moves along the ground will come to you to be kept alive. You are to take every kind of food that is to be eaten and store it away as food for you and for them." Noah did everything just as God commanded him.

Most people have through time read to this point and stoped.
Yet there is much more revealed if one was to read on...

Genesis 7:1-4
The LORD then said to Noah, "Go into the ark, you and your whole family, because I have found you righteous in this generation. Take with you seven of every kind of clean animal, a male and its mate, and two of every kind of unclean animal, a male and its mate, and also seven of every kind of bird, male and female, to keep their various kinds alive throughout the earth. Seven days from now I will send rain on the earth for forty days and forty nights, and I will wipe from the face of the earth every living creature I have made."

 
Now isn't this odd, take 7. . . a male and its mate. But seven is an odd number, and you can't make pairs out of an odd number.

So how does GOD count, when it comes to a male and his mate.

NIV Genesis 2:20-24
So the man gave names to all the livestock, the birds of the air and all the beasts of the field. But for Adam nosuitable helper was found. So the LORD God caused the man to fall into a deep sleep; and while he was sleeping, he took one of the man's ribs and closed up the place with flesh. Then the LORD God made a woman from the rib he had taken out of the man, and he brought her to the man. The man said, "This is now bone of my bones and flesh of my flesh; she shall be called `woman, ' for she was taken outof man." For this reason a man will leave his father and mother and be united to his wife, and they will become one flesh.

 
So GOD counts a united pair as one flesh. Therefore when GOD said ; Take with you seven of every kind of clean animal, a male and its mate, and two of every kind of unclean animal, a male and its mate,

...it was fourteen of every clean animal, and four of the unclean,and also fourteen of every bird...

...and so it follows that when he took some of all the animals, and some of all the birds to sacrifice to the Lord, he didn't make extinct all of the animals, had there only been two of each.

NIV Genesis 8:16-20
"Come out of the ark, you and your wife and your sons and their wives. Bring out every kind of living creature that is with you--the birds, the animals, and all the creatures that move along the ground--so they can multiply on the earth and be fruitful and  increase in number upon it." So Noah came out, together with his sons and his wife and his sons' wives. All the animals and all the creatures that move along the ground and all the birds--everything that moves on the earth--came out of the ark, one kind after another. Then Noah built an altar to the LORD and, taking some of all the clean animals and clean birds, he sacrificed burnt offerings on it.

 
I'm thinking this means we all need
to read a little further...