C++ Programming Code Examples C++ > Mathematics Code Examples C++ program to find LCM of two numbers C++ program to find LCM of two numbers To find the LCM (Least Common Multiple) of two or more numbers, make multiple of numbers and choose common multiple. Then take lowest common multiple, this lowest common multiple is LCM of numbers. For example; Suppose find LCM of 3 and 4 Multiple of 3 : 3, 6, 9, 12, 15, 18, 21, 24,....... Multiple of 4 : 4, 8, 12, 16, 20, 24, 28,..... So, common multiple of 3 and 4 is 12, 24 and Least Common Multiple is 12 LCM of 3 and 4 is: 12 #include<iostream.h> #include<conio.h> void lcm(int,int); void main() { int a,b; clrscr(); cout<<"Enter two numbers: "; cin>>a; cin>>b; lcm(a,b); getch(); // return 0; } //function to calculate l.c.m void lcm(int a,int b) { int m,n; m=a; n=b; while(m!=n) { if(m < n) { m=m+a; } else { n=n+b; } } cout<<"\nL.C.M of "<<a<<" and "<<b<<" is "<<m; }