Definition:Number Names/Welsh

Definition
These are the names of the numbers in Welsh:

The different forms for $2$, $3$, $4$ and their derivatives are for masculine and feminine.

The different forms for $5$ and $6$ are elisions for use in front of certain letters.

The different forms for $50$, $70$ and $90$ are separate ways of saying the numbers.

Note:
 * there are no distinct words for $11$ and $12$, indicating that there has been less influence of duodecimal systems on Welsh


 * there are clear indications of base $5$ and vigesimal influences as well as decimal


 * the interesting forms for $18$ (expressed as $2 \times 9$) and $50$ (expressed both as $10 + 40$ and $\dfrac 1 2 \times 100$).