Answer: They see 9 dogs in all.
Explanation:
Given : Ron sees 3 dogs at the park.
Hal sees twice as many dogs as Ron.
Then by using MULTIPLICATION OPERATION, we have
The number of dogs by Hal =

The total number of dogs they see in all will be
=Number of dogs seen by Ron+ Number of dogs seen by Hal
=3+6=9
Hence, they see 9 dogs in all.