I will spend hours hand-crafting what I believe to be fascinating bit of maths and then gently float it out on twitter only for it to sink without even a ripple. Then someone will notice that multiplication is distributive and the internet will ZOMG itself into a storm.
For example, this was racing across twitter today:
The most common response from the maths-purist is that such trivial bits of maths are “not interesting”. Unfortunately, I think we’re wrong by definition. If thousands of people have been amazed by something and forwarded it to all of their equally-stunned friends, then that trivial bit of maths has fulfilled all the requirements to be classified as definitely interesting.
And why shouldn’t it be. I spend a disproportionate amount of my life researching interesting maths puzzles for the already-maths-excited, why shouldn’t there be a different flavour of recreational maths for those who like their maths a bit more party-trick-esque?
If anything, these “facebook maths tricks” are a chance to explain – hopefully in an equally entertaining/simplified manner – some actual maths. It certainly shouldn’t be an opportunity to reinforce the maths-killjoy image by responding with “ah, I think you’ll fine that only works if you’re less than 100 years old” type pointless pedantry. If any centerians are on facebook, they can certainly defend themselves.
Here’s my explanation attempt from today:
I’m happy to go against the online maths-purist flow when it come to facebook maths. If anything, I’m only annoyed that I’m not good at coming up with them myself…
Write down a two-digit number. Subtract it from 11 times the sum of its digits. Is that interesting?