Find the greatest common divisor:
gcd(16, 20)
Find the divisors of each integer and select the largest element they have in common:
The divisors of 16 are:
1, 2, 4, 8, 16
The divisors of 20 are:
1, 2, 4, 5, 10, 20
The largest number common to both divisor lists is 4:
divisors of 16: 1, 2, 4, 8, 16
divisors of 20: 1, 2, 4, 5, 10, 20
Answer: |gcd(16, 20) = 4
