There's no E in odd, except for all of them

A fun little fact I learnt. It's disappointing that the word odd doesn't have an e in it. Even more frustrating - the word even has two e's in it!

 

Solution

One, three, five, seven and nine all contain the letter e. Eleven, thirteen, fifteen, seventeen, nineteen do as well.

The end digit determines a number's parity. Every odd number greater than 20 will end in one of the previously mentioned numbers.

Twenty five. Two thousand and nineteen. Six million and three as examples.

We can even include negative odd numbers in this!