ambA is worshipped through various mantras. Of these, panchadashI, shuddha ShoDashI, saubhAgya brahmavidyA or saubhAgya panchadashI (ShoDashI) and mahAShoDashI are the most important mantras in most of the dAkShiNAtya shrIvidyA sampradAyas. The number of letters in these mantras is indicated by the names of parAmbA based on katapaya calculations.
Name 1: lalitAmbA
La-3; li-3; tAm-6; bA-3
Total: 3+3+6+3 = 15 -> shuddha panchadashI
Name 2: lalitAmbikA
La-3; li-3; tAm-6; bi-3; kA-1
Total: 3+3+6+3+1= 16 -> shuddha ShoDashI
Name 3: shrIlalitAmbikA
shrI-2; La-3; li-3; tAm-6; bi-3; kA-1
Total: 2+3+3+6+3+1= 18 -> saubhAgya brahmavidyA
Name 4: shrIrAjarAjeshvarI
shrI-2; rA-2; ja-8; rA-2; je-8; shva-4; rI-2
Total: 2+2+8+2+8+4+2 = 28 -> mahAShoDashI
The same can be seen with respect to chaNDI as well. chan-6 and DI-3, thus indicating 6+3=9. On reversing the digits, the mantra denotes the thirty-six tattvas starting from shiva till dharA.