# The Welsh Number System

Welsh, being a Celtic language, traditionally used the base 20 (vigesimal) system. This system is common among adults, but not so common among children (who now use the newer base 10 system).

## Vigesimal System

Using a base of 20 means that numbers start counting again when you reach 20 instead of the modern (and common) 10. A few vestiges of this type of system exist in English (e.g Abraham Lincoln's Gettysburg Address: Four score and seven years ago...) as well as in other languages (French 80 quatre-vingts, lit. four twenties)

The numbers (1-20):

1 11 Un Unarddeg Dau Deuddeg Tri Tri ar ddeg Pedwar Pedwar ar ddeg Pump Pymtheg Chwech Un ar bymtheg Saith Dau ar bymtheg Wyth Deunaw Naw Pedwar ar bymtheg Deg Ugain

(Note deunaw literally means "two nines" - 18)

From this point, we count the same, only adding ar hugain (on twenty) at the end

21 Un ar hugain Dau ar hugain Tri ar hugain Pedwar ar hugain Pump ar hugain Chwech ar hugain Saith ar hugain Wyth ar hugain Naw ar hugain Deg ar hugain Unarddeg ar hugain Deuddeg ar hugain Tri ar ddeg ar hugain Pedwar ar ddeg ar hugain Pymtheg ar hugain Un ar bymtheg ar hugain Dau ar bymtheg ar hugain Deunaw ar hugain Pedwar ar bymtheg ar hugain Deugain

- This system repeats itself until 60 (note, 50 on its own is often called Hanner cant - half a hundred), and on again until 80

• Trigain - 60
• Pedwar Ugain - 80

When we get to 100, we use cant. This time, we use cant a/ac, thus:

• Cant ac un - 101
• Cant ac un ar hugain - 121 (literally One hundred and one on twenty)

## Further numbers

• Mil - 1000
• Deg Mil - 10,000
• Can Mil - 100,000
• Miliwn - 1 Million
• Biliwn - 1 Billion

## Decimal System

As Welsh language education took off, the difficulties of using a base 20 number when trying to teach children maths became apparent (three score and eleven minus three, anyone?), so a decimal system in common with other Indo-European languages was set up to make the teaching in Welsh simpler. This system has become common among the younger generation, in the same way the metric system has taken hold in the UK as a whole. The decimal system is very simply sum-of-parts: 34 is "three 10 four" tri deg pedwar, 20 is "two 10" dau ddeg.