For Hannah's birthday last year I made a list of facts about her age: year eight, eight facts. She didn't understand much of it but thought it was awfully cool that 8 laid on its side was the symbol for infinity. This year, it's 9 facts about Astonishing Number 9.

♥ Nine is the highest single-digit number in the decimal system

♥ Beethoven wrote 9 symphonies

♥ The expression being on cloud 9 means to be in a state of blissful happiness. Whereas a nine days' wonder is something that loses its appeal after a few days

♥ A group of nine of anything is called an ennead

♥ A polygon with nine sides is called a nonagon

♥ If you multiply nine by any natural number, and repeatedly add the digits of the answer until it is just one digit, you will end up with nine (*she loved this)

♥ A cat is said to have 9 lives

♥ Baseball is played with 2 teams of nine players each

♥ The 9-letter word redivider is the longest palindromic word in the English language

Happy Birthday, Hannah. And I'm sad you're not letting me do this anymore, but I certainly understand. Here's number 8 below:

8 placed on its side is a symbol for infinity

One computer byte is a grouping of 8 bits

A figure 8 is the geometric shape used in sports such as skating

A polygon with 8 sides is called an octagon (a stop sign is an octagon)

Oxygen is the element with an atomic number of 8 (and is represented by the symbol O)

All spiders, and more generally all arachnids, have eight legs. The octopus and its cephalopod relatives have eight arms, or tentacles

In chess, each side has eight pawns and the board is made of 64 squares arranged eight by eight

A figure-eight knot (also called Listing's knot) is unique in that it has four crossing points.

(Thank you, Wikipedia. I have one other source to credit but sadly cannot find my notes.)