pronunciation of the numbers six and dix

Question

I have heard that we shouldn't pronounce the "x" in six and dix before consonants. But in this exercise the "x" is clearly heard in "six mois". Is this correct, and if so is this pronunciation optional before a consonant? (I think I have heard it more frequently like "si-mois")

Accepted Answer

Bonjour Paul,
The letter X is pronounced [s] in 'six' or 'dix' they  are on their own:
J’en ai six / dix = I have six / ten of them.
If 'six' or 'dix' are in a number, then X is pronounced [s] :
dix-sept = seventeen /soixante = sixty
X is also pronounced [z] in numbers derived from 'deux, six or dix':

deuxième = second
sixième = sixth
dixième = tenth
dix-huit = eighteen

I hope this helpful.
Bonne journée!