Start out simple.
What are the multiples of 8?
The multiples of 8 would be:
1,2,4,8
What are the multiples of 10?
The multiples of 10 would be:
1,2,5,10
What are the multiplies of 12?
The multiples of 12 would be:
1,2,3,4,6,12
Now, go and circle the common numbers.
They would be:
1 and 2