Project 6, 2015  Research Experience for Teachers  Project 4, 2016 

Inverse of m Modulo n 
Enter a number m and a number n in the boxes at the
top left. Click on Start to begin the gcd algorithm for
finding the inverse of m mod n. Repeated clicks on
the Next button will update an equation
R = U*m + V*nwhose values are shown on the bottom line of the applet in separate boxes. When an inverse is found, if it exists, it will appear in the box labeled inv:. One click later, the check field will verify this by showing a 1. If an inverse does not exist, "None" will appear in the inv: box. 
Further details:
Boxes larger and smaller contain the two numbers
that the algorithm is currently trying to find the greatest common
divisor for. Initially these numbers are m and n.
The box labeled divisor shows the number of times the
smaller number divides the larger number, and the
box labeled remainder shows the remainder of that division.
There are two rows of three columns that record numbers which are
used to compute new factors. Initially these are:
