In case you don't know, Fibonacci numbers are those in a series where the next number is always the sum of the 2 previous numbers. the series always starts with 0 and 1.
so, the series is 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, etc.
If you google Fibonacci numbers you will find all kinds of interesting info concerning these numbers and nature, architect and history. quite interesting.
But for our purposes today, we just want to make a quilt block (or 12). LOL
You start with 2 yards of fabric...1 of each light and dark or contrasting or coordinating or whatever you like. if you cut the fabric exactly as the numbers indicate, you will be able to make 4 blocks from the 2 yards of fabric and your blocks will come out 18" square. if you add 1/2" to the numbers for seam allowances you will only get 2 blocks for your 2 yards of fabric and your block will be 19 1/2" square (19" after using it in a quilt.)
take a piece of paper and draw 5 little squares on it. this will be your 'pattern'. in those squares put the numbers 1, 2, 3, 5, 8...in no particular order. but once you put your numbers in, don't cheat and change them.
in my first blocks with my black and white fabric like this i used 3 2 8 1 5 as my number sequence that went into the little squares:
they became these blocks. i cut them as indicated without adding seam allowances and came out with 4 blocks that were 18" square. you will get 2 of each colorway.