Editing Ethnomathematics (section)

=====Welsh=====
Counting in Welsh combines the vigesimal system (counting in twenties) with some other features.{{citation needed|date=March 2020}} The following system is optional for cardinal numbers nowadays, but mandatory for ordinal numbers.

{|class="wikitable"
|+Examples of numbers in Welsh
|-
|14||pedwar ar ddeg||four upon ten
|-
|15||pymtheg||five-ten
|-
|16||un ar bymtheg||one on five-ten
|-
|20||ugain||score
|-
|37||dau ar bymtheg ar hugain||two on five-ten on score
|-
|57||hanner cant a saith||half hundred and seven
|-
|77||dau ar bymtheg a thrigain||two on five-ten and three-score
|-
|99||cant namyn un||hundred less one
|}