"Vestanam," which means "By Osculation," is a powerful technique for divisibility tests, especially for prime numbers. It allows us to break down a large number into a smaller one that's easier to check.
The term Vestanam relates to "osculation" or "kissing". In mathematics, it refers to the point of contact or tangency. Swami Bharati Krishna Tirtha used this term to describe a method where digits "touch" or influence the rest of the number to reveal divisibility.
To test divisibility, we repeatedly multiply the last digit of our number by a special number (the "osculator") and add/subtract it from the rest of the number.
Enter a number and a divisor (ending in 1, 3, 7, or 9) to test for divisibility.
Get 20 practice problems with answer key
Vedic and Trachtenberg tricks are powerful, but they work best when you have mastered the basics. Join The Academy to perfect your Addition, Subtraction, and Multiplication skills with fun games and rewards.
Launch The AcademyFree for all students • No ads • Safe & Secure
Magic Math! Solve complex calculations instantly just by looking at them. Master the Vilokanam Sutra to spot answers without calculators.
Tired of large digits? Learn to remove 6, 7, 8, and 9 from calculations using Vinculum numbers for faster, simpler mental math.
The ultimate math cheat sheet. 10 techniques to speed up your calculations by 1500% for SAT, CAT, GRE, and Banking exams.