Age: Tricky one. If you're talking about the number itself, you might take your starting point as the emergence of the base-10 system, in which case the answer is approximately 5,100 years. If, however- ...
We've only got 350 words to play with. Appearance? That depends. You may know it as a pair of words, one being "seven" and the other being "billion", but it also occurs as 10 digits, often divided by commas, full stops or spaces, depending on local convention. The first of those digits is 7, the second is 0, the third is 0, the fourth– ...
Yes, thank you. I sometimes feel Pass notes suffers from an overly rigid format. That's not a question. You're supposed to ask questions and I'm supposed to answer them.
All right, smartypants. What's so important about seven billion? That's how many humans will soon be on earth, according to the UN. On 31 October, to be precise.
That's scary! Isn't it? That's a billion more than 12 years ago. There will be more than nine billion of us by 2050 and 10 billion by the end of the century.
No, it's scary that this seven billionth baby will be born on Halloween. He might be the Antichrist. Or have a head like a pumpkin. That's not how science works. But human number 7,000,000,000 probably will be a he.
Because … Because he is likely to be born in the Asia-Pacific region, where there are 110 little boys to every 100 girls.
How does anyone know this? Censuses and that.
That doesn't sound very scientific. Sorry – censuses inter alia.
Don't people lie on census forms? Er …
And doesn't that make 31 October a bit of a guess? Well … The US Census Bureau is putting its money on next February.
And doesn't this in turn mean this entire Pass note is based on an eye-catching oversimplification? That question certainly deserves an answer. But, just like humanity …
Yes? We're running out of room.
Do say: "What's a few million between friends?"
Don't say: "One, two, three, four …"