A factor is any number which the original number can divide into evenly. A common factor is a number which is a factor of both numbers being considered. In this case, we have 1. The only nunmber 1 can divide evenly into is 1, and thus this is the only common factor between it and 7. Therefore, the GCF of 1 and 7 is 1.
The GCF is 1.
The GCF is 1.
The GCF is 1.
The GCF is 1.
The GCF is 1.
The GCF is 1.
The GCF is 1.
The GCF is 1.
The GCF is 7.
The GCF is 1.
The GCF is 1.
The GCF is 1.