I’ve just realised that Dutch rekenen and English reckon are closely related.

And as an extra, some  compound verbs with the same stem from vandale.nl:
afrekenen – settle (up), settle/pay one’s bill, settle one’s account(s): mag ik afrekenen?
aanrekenen – blame (for)
inrekenen – pull in, round up (Also see http://context.reverso.net/vertaling/nederlands-engels/inrekenen)
meerekenen – count (in)
narekenen – go over (again), check
omrekenen – convert (to), turn (into)
uitrekenen – calculate, compute
voorrekenen – figure out, work out