The Greatest Common Factor (GCF) of 80 and 40 is 40. The GCF is the largest number that divides both numbers without leaving a remainder. To find the GCF of 80 and 40, you can list the factors of each number and identify the largest common one.
Factors of 80: 1, 2, 4, 5, 8, 10, 16, 20, 40, 80
Factors of 40: 1, 2, 4, 5, 8, 10, 20, 40
The largest common factor is 40, so the GCF of 80 and 40 is 40.