This is wrong to say that only the western astrologers know the malefic or benefic attributes of number. From the very ancient times, the Indians have also recognized the effects of the same.
English Numerologist Sepharial has classified these Yantras in three categories in the following manner:
According to Sepharial, the number is the symbol of completeness or the god Almighty. The western astrologers think it to be associated with Saturn. According to Indian astrology, the Yantra of 15 (C) is used to ward off the distress and agonies. It showers its auspicious effects, if it is cast on a sheet of Bhojapatra properly with Astagandh ink and worn in a silver or copper talisman. The method of casting this Yantra of 15 has been mentioned in the following Shlok in Panchadashi Tantram.
The numbers 1, 2, 3, 4, 5, 6, 7, 8 and 9 have been used in the following Panchadashi Mahayantra.
The Panchadashi Yantra cast above dates back to our ancient times. To cast this Panchadashi Yantra on the wall of a house on the occasion of Dipaawali has been in practice in our country since ancient times. The shopkeepers cast this Yantra in their shops, cash boxes and safes writing 'Shubh Labh' with it. This shows that it was in practice before Sepharial also. This is said that Sepharial had come to India and learnt this system of numerology from an Indian saint. The Yantras have been mentioned elaborately in different scriptures like Tantrasaar, Mantra Mahodadhi, Mantra Mahaarnava, Tantraraaja Tantre, Yantra Chintamani etc. Below, Yantras of all the Planets are mentioned, all of which are under the shadow of Panchadashi Yantra. The Panchadashi Yantra should be worn for benefic results of the Sun. Here, a short description on how to cast Yantras according to the theory of scriptures and which number should be written in which box is given below.
That is, saints like Garg say that if worn, these Yantra may save the natives from different diseases, distress and agonies.
Meaning thereby, this Yantra wards off the malefic effects of the Moon.
Rishi Garg says that this Yantra saves from the malefic effects of Mars that it showers in its Dashaa-Antardashaa while it is in transit or in a debilitated sign or house. This saves also from loss of bliss of child, problems in blood etc.
This Yantra saves the natives from ailments caused due to the disturbed state of bilious humour within the system, skin diseases etc. This also saves from loss in business and contrariety from friends. In short, the natives should wear this Yantra to save themselves from the malefic effects of Mercury.
This Yantra saves the natives from the malefic effects of Mars while it is in transit or in Mahadasha.
Saints have mentioned that the Yantra of Venus saves the natives from the malefic effects of Venus.
The Shani Yantra cast on Bhojapatra should be worn. Whosoever is scared from the malefic effects of Saturn? Whosoever is there to whom the Saadhe-saati does not harass? If unfavorable, Saturn causes loss of honour, wealth, physical ailment, mental agony and many other diseases. The Yantra should be used to ward off all these problems and agonies.
Rahu Yantra should be worn to ward off distresses and agonies caused by Rahu
People should wear Ketu Yantra all the time to ward off agonies and afflictions caused by Ketu.
Western astrologers do not take Yantra so seriously, but in India, it has been discussed elaborately in different old scriptures. This is difficult for us to know as to how our ancient Rishis Muni’s came to know that the numbers placed in the order stated above could give so effective results. It was their skill that gave this knowledge to the world. We are merely following what they left for us.