math
posted by Anonymous .
The number uses every number 09 the numbers are used only once the fourth digit is 4 the first digit in the billions place is 3 the 5 is next to the last digit the sixth digit is 7 the digit after 3 is 9 the digit before 5 is 2the third digit is half the value of the eigth digit the last digit is twice the amount of the fourth digita 0 precedes the 7the seventh digit is the sum of the 1st and 4th digit

The problem would be easier to solve if you would break it up into capitalized sentences. What you have written is a runon sentence that is difficult to follow.
You should have written:
The number uses every number 09.
Each number is used only once.
The fourth digit is 4.
The first digit in the billions place is 3.
The 5 is the nexttothelast digit.
The sixth digit is 7.
The digit after 3 is 9.
The digit before 5 is 2.
The third digit is half the value of the eigth digit.
The last digit is twice the amount of the fourth digit.
A 0 precedes the 7.
The seventh digit is the sum of the 1st and 4th digits.
Fill in the blanks, step by step, according to the directions above.
Example
4
345
394625
3914625
etc.
You finish it 
The sixth digit is 7 not 6

It wouldn't let me break down the way you have it. it all looks like what I put other than the 6 should be a 7, if I understand right.

Correct. The sixth digit is 7.
My mistake. Anyway, you get the idea.
If that is the way the question was written, you should be learning math, and grammar, somewhere else.
391407_258
The only digit left to fill the blank is 6.