For multiplying 20 times 4, we get 80 [dz], which is the first letter of word oil [dzyut] in Armenian. And substituting the letter 400 [n] for 80 [dz], we change the word oil [dzyut] in to the word for matter [nyut], which symbolizes the new leaven that miraculously raises up the lump of dough.
While in the present day Eastern Armenian literary language letter Ձ is muffled and sounds like [ts] in certain positions, in the Western Armenian it is muffled in all positions. According to Hrachya Atcharyan, one of the most respected researchers of the history of the Armenian language, the graphic form of the letter is derived from the Armenian Ծ [ts].
According to the versions supported by otherscholars, its prototype is letter Զ [z]. Ձ is the first letter of the “Book of Lamentations” written by Grigor Narekatsi. The author tries to interpret the mystic symbolism of the Holy Chrism through the numerical value of letters of the Armenian alphabet: Now, if using the numerical value of the [Armenian] alphabet,we take letter [dza] with the value of 400 [n], and apply it to the profound mystery of the oil, we come up with easily digestible explanationto nourish those hungry for understanding.
For multiplying 20 times 4, we get 80 [dz], which is the first letter of word oil [dzyut] in Armenian. And substituting the letter 400 [n] for 80 [dz], we change the word oil [dzyut] in to the word for matter [nyut], which symbolizes the new leaven that miraculously raises up the lump of dough. And as the Gospel parable teaches, though the smaller [80] does not contain the larger [400], still it can transform the whole mass and make it grow, so the anointing oil mixed into our nature transforms and makes us grow.
As we can see, the numerical value of the first letters of the words ձիւթ [dzyut] and նիւթ [nyut] is used by Narekatsi as a method to “explain the depths of the mystery”. It is notable that even medieval interpreters of Narekatsi indicated the Greek letters П (pi) and Υ (upsilon) next to the Armenian letters Ձ (dza) and Ն (nu). The reason is that these are the first letters of the Greek equivalents of the Armenian words “dzyut” and “nyut”: πισσα ([pissa] – resin) and υλη ([yule] – substance, matter). Besides, the numerical value of П and Υ in the Greek alphabet is identical to the value of letters Ձ and Ն in the Armenian alphabet – 80 and 400.
See more at Aram Khachaturians "Armenian Alphabet. History and Symbolism" book