Based on what this old woman with no techie talent gets from that discussion, the answer to my question is YES. Would like to have this specifically confirmed for the iphone 4 I inherited from my grandson.
Turn OFF cellular data
Turn OFF data roaming
Turn ON or OFF airplane mode? not sure on this one..............
After purchasing AT&T international texting plan, send 50 texts and receive unlimited text messages and I'll only pay the $10 for the AT&T plan - incurring no other charges.