The Euclidean algorithm works with numbers of any size. To find the greatest common divisor of 77 and 187 using the Euclidean algorithm involves the process of long division, which you might have ...

Thomas Koshy, 80.48 The Euclidean Algorithm via Matrices and a Calculator, The Mathematical Gazette, Vol. 80, No. 489 (Nov., 1996), pp. 570-574 ...

Stan Wagon, Editor's Corner: The Euclidean Algorithm Strikes Again, The American Mathematical Monthly, Vol. 97, No. 2 (Feb., 1990), pp. 125-129 ...