基数词和序数词
41.
| 一，etc. | 第一，etc. | |
| I | un | cyntaf |
| II | m. deu, f. dwy | eil |
| III | m. tri, f. teir | m. trydyd, f. tryded |
| IV | m. petwar, pedwar, f. pedeir | m. petwyryd, petweryd, f. petwared (或者pedwyryd, etc.) |
| V | pump | pymhet |
| VI | chwech, chwe | chwechet |
| VII | seith | seithvet |
| VIII | wyth | wythvet |
| IX | naw | nawvet |
| X | dec, deng | degvet |
| XI | un ar dec | unvet ar dec |
| XII | deudec | deudegvet |
| XIII | m. tri, f. teir, ar dec | m. trydyd, f. tryded, ar dec |
| XIV | m. petwar, pedwar, f. pedeir, ar dec | m. petwyryd, etc., f. petwared, etc., ar dec |
| XV | pymthec, pymtheng | pymthegvet |
| XVI | un ar bymthec | unvet ar bymthec |
| XVII | m. deu, f. dwy, ar bymthec | eil ar bymthec |
| XVIII | m. tri, f. teir, ar bymthec | m. trydyd, f. tryded, ar bymthec |
| XIX | m. petwar, pedwar, f. pedeir, ar bymthec, un eisieu o ugein | m. petwyryd, etc., f. petwared, etc., ar bymthec |
| XX | ugeint, ugein | ugeinvet |
XXI.-XCIX. 在O.W. trimuceint 用来表示thirty。但更常见的做法是以20记: deugein(t) (O.W. douceint) ：40, deugeintvet：第四十, trugein(t)：60, trugeinvet：第六十, petwarugein(t) ：80, petwarugeinvet：第八十。中间的的数字用加法得到,e.g. un ar hugein(t) 二十一, dec erydyr ar hugeint：三十个犁, detidec brenhin ar hugeint：三十二个国王, deng mlyned a feugemt：五十年, deudeng mlyned a thrugeint：七十二年, petwyryd ar ugeint：第二十四。这种计算方法可以延伸至百位数以上, e.g. pedeir gwlat a seith ugeint 一百四十四个国家。
C.-M.Cant：一百, canvet：第一百. 由此其他百位数由基数词添加前缀获得: deucant或 deugant, trichant, petwarcant, pumcant, chwechant, seithcant, wythcant, nawcant. Mil：一千, dwy vil：两千, etc. Un vlwydyn ar bymthec ar hugeint a deucant = 236年; chwech marchawc a thrugeint a phumcant：566个骑士; deudeng mlyned a thrugeint ac wythcant 872年; deg mlyned a phetwar ugein a chant a mil：1190年, myrd：一万。