In this field, the results of any mathematical operation (addition, subtraction, multiplication, or division) is reduced modulo 13; that is, multiples of 13 are added or subtracted until the result is brought within the range 0–12.
Dǎɣ tabarat ten, igarawan ən tədas ən maɗinan (asiwiɗ, ukis, asinimi ƭif meɣ tizune) aqalan ayfnazan modulo 13, atamosan anmitif ən 13 aqalan awiɗan meɣ ukis hawendǎɣ har agaraw eqal aditiwawayan dǎɣ efay 0-12.