Leonardo fibonacci was lived in pisa around 1200 and gave his name to the fibonacci numbers.

The fibonacci sequence is a popularized Hindu-Arabic number system which is also know as the decimal system. (1, 1, 2, 3, 5, 8, 13..................)

1- The first 1 represents a pair of baby bunnies born- 1 pair of bunnies.

1- The second 1 represents a pair of babies grown up.

2- Two respresents the parents plus the babies.

3- Three represents the parents have two more babies.