Although you may or may not deliberately chose a number, each human brain is intrinsically random.
To make this scientific and statistically consistent, Only ONE number per person per 24 hour day maximum please, including fractions.
Any size or style of number, as long as it fits within a text box without a side bar. Don't get too clever. You may leave a reason for your selection.
If you only text and choose not to leave a number, the previous person's number will be halved and used as your default number. Digits hidden in text do not count.

My first number is

1

Just because I can !

99
Maxwell Smart's sexy offsider. Do you get it yet ?

42
Life, The Universe and Everything

(I get it but its not really important to me)

–273.15
–459.67
Absolute Zero

5,878,625,373,183.6
One Light Year in Miles

5280
One mile in Feet

1,000,000,000,000,000,000,000,000
Represents the metric prefix "Yotta"
also known as septillion

1.602176565(35)×10^19
The value assigned to one electron volt

57

When I closed my eyes without reading beyond the OP, that was the first number to pop into my head.

Purely random? Coincidence? Or some kind of subliminal suggestion?

3
Because it looks like something else.

12
Cuz 1+1 is 2 and (1)(1) is 1
Write it side by side and you have a beautiful number 12

8

Because when turned on its side, it means infinity.

33... It's the sum total of my birthday when adding each number together.

1961
Was a good year

12
a popular number

24

The year I bought my first brand new car

5

The number of times I sent a tweet to Halle Berry on Twitter before she answered me.

333

The number of the Midget Beast.

I was born in 1956

Also I love my 1911

451
Farenheit

144
12 sq

64,000

997

A completely random number that popped into my head.

7

The number of times this week I ran my car through a car wash to remove bird poop. I swear they are out to get me.