Number 1

"Take a census of the whole Israelite community by their clans and families, listing every man by name, one by one.  You and Aaron are to count according to their divisions all the men in Israel who are twenty years old or more and able to serve in the army...From the descendants of Judah: All the men twenty years old or more who were able to serve in the army were listed by name, according to the records of their clans and families.  The number from the tribe of Judah was 74,600." vv.3,27

Read chapter 1
We now start the book of Numbers.  Many people say they don't like this book because all it is is lists of numbers and names.  So maybe the first chapter starts off like that but there are many stories throughout this book and one of my favorite stories of the whole Bible is found in the book of numbers (you'll have to keep reading to find out!).
Well in this first chapter we see the Lord tell Moses and Aaron to take a census of the whole Israelite community of men twenty years old and up.  So the total number they have of 603,550 (in verse 46) is only of men 20+ and doesn't include women, children and the whole tribe of Israel.  Can you even imagine how many people that would be if the whole entire population was counted?!  If you think conservatively on this of one wife for every man and one child for every couple (603,550 x 3) you would have 1,810,650.  That's a lot of people living and wandering in the dessert to the promise land (they weren't just a city that stayed put but all packed up and moved often for 40 years).  The people were numbered to show them God's faithfulness of increasing them and not letting the house of Israel die out.  It's interesting too to compare how many men numbered in the different tribes.  The tribe of Rueben, who was the firstborn of Israel, doesn't have the largest number which we could wonder if this is because of Genesis 49:3-4 having lost his dignity.  Also note that Judah has the largest population of all the tribes.  We know the Lord came from Judah and this could be from the blessing Issac gave him too (Genesis 49:8-12).
God's a mathematician, even if you're not see the magic in numbers and God's perfect and faithful ways.