ब्राह्मस्फुटसिद्धान्त (ब्रह्मगुप्त - शून्य, कुट्टक, बीजगणित एवं सम्पूर्ण २१ अध्याय सान्वय सटीक)

162 BRAHMAGUPTA AND ARITHMETIC
The method has been more clearly enunciated by Mahāvīra
(850 A.D.) in the Gaṇitasārasaṁgraha :
Having squared the last (digit), multiply the rest by
the digits by twice the last, (which) is moved forward
(by one place). Then moving the remaining digits con-
tinue the same operation (process), This gives the
square.¹
Brahmagupta's method of squaring is shown by the follow-
ing example :
To square 125.
The number is written down
125
The square of the digit in the last place, i. e., 5²=25 is set
over it thus :
25
125
Then, 2 x 5=10 is placed below the other digits, and 5 is
rubbed out, thus :
25
12
10
Multiplying by 10 the rest of the digits, i.e., 12 and setting
the product over them (the digits), we have.
1225
12
10
Then rubbing out 10 which is not required and moving the
rest of the digits, i. e. 12 we, have
1225
12
Thus one round of operations is completed.
Again as before, setting the square of 2 above it and 2×2=4
below 1. we have
1625
1
4

1. GSS. P. 12.