slang and HP - Reckon

[Steve]

I'm curious about the word 'reckon'. 

Do people in Britain actually use that word as much as we see it in
the book? 

Harry and Ron use it all the time. The only people I know of who
consistently use that word in everyday speech are driving pick-up
trucks around that great state of Texas.

Of all the language, Brit-speak, slang, etc..., 'reckon' was the one
word that struck me as the most odd.

Just curious.

bboy_mn