Bharati Krishna Teerthaji got his revelations from a particular portion of the Atharvaveda called the Ganita Sutras. The Ganita Sutras are also called Sulba Sutras, "the easy mathematical formulae", that's the meaning of the expression. Now these texts were in Sanskrit and the grammar, the literature and the figures of speech in Sanskrit give great facility of expressing one's dispositions in a number of different subjects but with the same set of words. Hence it becomes difficult for a person to understand the different layers of meanings encoded in one text.
Bharati Krishnaji underwent meditation for long years in the forest of Sringeri. He took the help of lexicographies, lexicons of earlier times, because as a language develops and comes in context with other languages words change their meaning. Words get additional meaning, words get deteriorated in meaning. So Bharti Krishnaji studied old lexicons including Visva, Amara, Arnava, Sabdakalpardruma etc. With these he got the key in that way in one instance and one thing after another helped him in the elucidation of the other sutras (formulae).
It was to His Holiness's extreme amazement that the sutras dealt with mathematics in all its branches. He realized only sixteen sutras cover all branches of mathematics _ arithmetic, algebra, geometry, trigonometry, physics, plain and spherical geometry, conics, calculus, both differential and integral, applied mathematics of various kinds, dynamics, hydrostatics, static, kinematics and all.
~ From Vedic Metaphysics - by Bharati Krishna Teerthaji Maharaj