It is actually easy.
On LCM:
Just count by the numbers then find the same exact multiple.
Example: 4 and 6
4 : 4, 8, 12,
6 : 6, 12
The LCM is 12.
On GCF:
Just find the factors of two numbers then find the common of its factors, next is too identify the greatest one.
Example: 4 and 6
4 = 1, 2, 4
6 = 1, 2, 3, 6
Common Factors: 1 and 2
Greatest Common Factor (GCF) : 2
