C :: How To Prompt User To Scan Numbers Into Array

i need to prompt the user of my program to input numbers into an array so that later on these numbers can be added or subtracted with other numbers to form a new array. My problem is I don't know how to make the user input numbers which will then be saved into the array for later use. Here is the parts of my code that relate to the problem:

Code:

float Xv, Yv, Zv, Xu, Yu, Zu ;
float vector1[VECTOR_LENGTH] = {Xv, Yv, Zv} ;
scanf("%1f %1f %1f", &Xv, &Yv, &Zv);
printf("The first element in the array vector1 is: %3f
", vector1[0]);

The point of that printf function is to see if what they have entered is actually registering as what i want it to. This does not work however and the value for this always comes up as 0.

how to scan numbers into an array so that they can be used for later use?