Do I need a tourist visa extension (DTV) if I'm entering Thailand multiple times for short stays?

Good day dear fellows,

Just to clarify one situation to assess my situation if need dtv or not yet..

Scenario:

1-)10 April entry, 20 april exit.

2-)27 April entry, 01 june exit.

3-) 15 June entry, 10 July exit.

Each entry probably one or two month visa exemption stamp will be put on passport however i will not use all days assigned to me. I will stay as a tourist but time to time need do dubai or europe for business.

Appreciated for any useful comment..