By Periyava
Translation from Tamil: V. Krishnaraj

                                 த்வைதம் ÷ பெளத்தம் = அத்வைதம் : தெய்வத்தின் குரல் (முதல் பகுதி)
                                                                                       Dvaitam + Bhaudam = Advaitam

Braḥmam is Pūraṇam (Fullness, completeness, perfection). The world is Fullness. The world as fullness dawns in the complete and perfect entity, Braḥmam. If world as fullness is removed from Braḥmam, the latter remains as Fullness, according to a Mantra in Upanishad. Fullness means all. How could two entities be called Pūrṇam? A question arises, when you take off Pūrṇam from Pūrṇam (world from Braḥmam), how could the remainder be Pūrṇam?
What is the meaning of this Mantra? The world in truth did not split off from Braḥmam. Braḥmam Itself appears as the world. Braḥmam did not create this world from other extraneous ingredients. Braḥmam did not transform into this world. It is just that Braḥmam makes an appearance as the world.

In the night, we see a garland and think it is a snake. Now, the garland appears as the snake. The garland did not transform into a snake. The garland did not create the snake. Once snake is imagined, it (the garland) completely appears as a snake in fullness. If we discover it is a garland, in its fullness it is a garland. In the Pūraṇam of the garland, the Pūraṇam of the snake dawned. (Some call this Superimposition of snake on garland.) Likewise, In the Braḥma Pūraṇam appears the world Pūraṇam. (God appears as the world. God is the world. Is God projecting himself as the world, the universe...?) That is, in one state the garland is the Pūraṇam; in another state the snake is the Pūraṇam. There are no two Pūraṇams. One Pūraṇam on two occasions appear as two Pūraṇams. In the garland, had the appearance of snake added to its weight? No. When the realization that it is a garland became clear and the appearance of the snake died, did the weight of the garland go down? That was not the case here.

If the world or universe is added to or subtracted from Braḥmam, the latter remains an unchanged Pūraṇam. Kambar states, the world is the Māyā-snake (illusory snake) appearing in the garland and a false (illusory) snake appearing in the garland. When the snake is deducted from the garland, it remains as the Pūraṇa garland. This is what is said in the Upanishad, “When Pūraṇam was deducted from the Pūraṇam, what is left (after deduction) is Pūraṇam. (When you add to or subtract an illusory object from a real object, there is no change in the latter by any parameter.) Why did the garland appear as the snake? Darkness made it look like it. The Braḥmam appears as the world in the darkness of Māyā. Māyā means “That which is not.’’ The non-existent Māyā makes the one and the only Braḥmam appear as multiplicity of objects of the universe. Can non-existent entity act like this? I will answer it in a mathematical sense.
That which is not. = That which is non-existent.
In matters of Braḥmam, we considered, addition, subtraction, and other mathematical models. Addition does not end in increment in our garland-snake model. We saw the wonderous stability in that subtraction does not compromise its Pūraṇam. Let me bring to your attention the mathematics of multiplication and division for illustrative purposes.
We divide the dividend (20) with a divisor (2). The quotient is 10.
The quotient increases as the divisor becomes smaller. Examples: 16/16 = 1. 16/8 = 2. 16/4 = 4. 16/1 = 16.
We divide one number with another number. When the divisor is 0, the quotient becomes larger and larger in relation to the rising dividend, goes beyond the boundaries of counting and results in Aṉantham (infinity).
1/0 = Aṉantham; 2/0 = Aṉantham ; 3/0 = Aṉantham. Same with ten million divided by 0 = Aṉantham. When quotient is multiplied by divisor, the dividend is obtained.
Infinity x 0 = 1
Infinity x 0 = 2
Infinity x 0 = 3
One Aṉantham (infinity) goes on forever with no end. One Aṉantham multiplies ad infinitum with 2, 3, 10 million…. That one Aṉantham is Braḥmam. The non-existent Māyai is zero. What is not is cipher. Māyai means ‘that which is not.’ Māyai is cipher, zero, naught, nil, nada, nothing, zilch and zip. Aṉantham (Infinity) multiplies itself by zero and shows itself as many and varied. Likewise, Braḥmam by Māyā Sakti shows itself as countless and infinite entities of this universe.
The dividend that is the universe can have any numerical value. Whatever may be its numerical value, the divisor is the unchangeable (fixed) zero-Māyai. Aṉantha Braḥmam becomes the quotient. (This Aṉantham is Braḥmam. The non-existent entity is zero.) The universe as the dividend could be assigned any numerical value. When the divisor is zero-Māyai, the dividend and the quotient are the same. Aṉantham Braḥmam itself becomes the quotient. The universe can be assigned any number. Since it could be an infinite number, it becomes an Aṉantham. There is so much of variability in creation. Our mind runs in a multiplicity of ways. There is no end to it. Upanishadic Mantras declared Braḥmam as Pūraṇam. It is changeless Aṉantham. When the universe is declared as Pūraṇam and since it is constantly changing, we take Aṉantham as its meaning. The mutable and  mutating entity cannot be Satyam. Though we give it a value (1, 2, 3, million, 10 million, 100 million), in truth it is Asatyam-non-existent-, and it is a zero. 
Whatever number is multiplied by zero, the resulting number is zero. That is the mathematical rule. Aṉantham (Braḥmam) x Māyai (0) =1;2;3… are a figurative model. In truth, the product of Aṉantham multiplied by Māyai is the universe, the Māyāmayam (Illusion-Repletion) that is zero. Advaitam states, Aṉantham (Infinity) is the sine qua non of Braḥmam, which alone is Satyam. Dvaitam says the universe appearing as Aṉantham is Satyam. Bauddham says Braḥmam and the universe are non-different, Sūṉyam, zero, and Māyai. That is, Braḥmam is Satyam according to Advaitam. Bauddham declares all are Māyai. Dvaitam says the universe is Satyam.
பெளத்தம் pauttam , n. Bauddha. Buddhism.

Braḥmam X Māyai = Pirapañcham (Universe)
Advaitam X Bauddham = Dvaitam (Duality).
Dvaitam ÷ Bhaudam = Advaitam (Monism).