* Cube roots: It began with extracting cube roots of large numbers, which she could do in her head rapidly while still a child in the 1930s. ... This means that 46,295 multiplied by itself seven times yields that number of 27 digits; Shakuntala Devi worked backwards from the 7th power to derive the root.

How did Shakuntala Devi learn mathematics?

Shakuntal Devi was a born genius. She was totally a self learner. She was daughter of circus performer and she used travel with her parents when she just three years old. It has been learnt that card tricks helped her develop the skills of calculation.

How is Shakuntala Devi calculated?

Shakuntala Devi demonstrated the multiplication of two 13-digit numbers in just 28 seconds. She could also tell the day of the week of any given date in the last century spontaneously.