These Saraswati Mantras can be counted any time during the day or night and there is no fixed Sadhana-Vidhi or Puja procedure prescribed for the practice of the Mantras. The practitioner can select anyone of these Mantras as they are all for the same purpose, which is acquisition and enhancement of knowledge.
ॐ शारदामातायै नमः ||
Om Shardamatayai Namah ||
ॐ शारदामात्रे नमः ||
Om Shardamatre Namah ||
Both the Saraswati Mantras given above are essentially variations of each other with the same meaning, which is – Namaskar to Saraswati Mata. These Mantra will prove extremely beneficial if chanted 900,000 times in a lifetime.
ॐ ब्रह्मपुत्र्यै नमः ||
Om Brahmaputryai Namah ||
The meaning of this Mantra is – I Salute the Saraswati who is the daughter of Brahma.
This Saraswati Mantra as per the scripture will prove most beneficial if chanted 700,000 times in a lifetime.
Note- The Saraswati Mantra will start showing very positive results in a short period of time, like a few days. The recommended Mantra Chants are given because the Mantras will start showing their most positive results when this limit is reached and the practitioner is free to discontinue the Mantra Sadhana.
Some years back, I had given a couple of simple Saraswati Mantras for students. These Mantras can also be chanted by the seekers of knowledge and the recommended Mantra Chants as per the text is 700,000 Mantra chants. That post can be seen here- Simple Saraswati Mantra Mantra Sadhana for Students