You need at least two numbers to find a GCF. If that's 20 and 24, the GCF is 4.
The GCF is 36.
The GCF is 4.
The GCF is 6.
The GCF is 9.
The GCF of 18, 12 and 36 is 6. The GCF of 1812 and 36 is 12.
The GCF is 6.
The GCF is 36.
The GCF is: 6.
The GCF is 36.
The GCF is 4.
The GCF is 9.