In Jain practice, there isn’t a universal rule that you must prefix “105” in front of Mataji in all contexts. The use of the number 105 is more of a local or temple-specific convention rather than a canonical Jain scriptural rule.

Possible reasons you might see “105 Mataji” used:

• It can denote a set of 105 names or forms of a goddess or revered mother figure that devotees chant or honor in a particular puja.
• Some temples or family rituals use a fixed count (such as 105) to structure prayers, meditations, or offerings in a predictable, easy-to-repeat format.
• It may be a practice unique to a specific Digambar or Shwetambar community or region, not a general rule shared by all Jains.

Important notes:

• Mataji, in Jainism, can refer to reverence shown to a venerable female figure (such as a respected nun or a goddess in local devotion). The way she is honored (including any numbering) can differ between communities.
• There is no single, authoritative Jain scripture that mandates prefixing “105” to Mataji for all followers.

If you can share where you saw this (a particular temple, book, or tradition), I can give a more precise explanation grounded in that context.