Complex sentence: Oral rehydration solutions (ORS) with modest amounts of salts and zinc tablets are the treatment of choice and have been estimated to have saved 50 million children in the past 25 years.
Split into simpler sentences: Oral rehydration solutions (ORS) with modest amounts of salts and zinc tablets are the treatment of choice. They have been estimated to have saved 50 million children in the past 25 years.