Job Outlook. Excellent. Respiratory therapists provide care and treatment for patients suffering from breathing and cardiopulmonary difficulties. They may also provide emergency medical care for patients who have experienced asphyxiation, heart attacks, or shock.
0 is a number alone or not. if you put 0 by itself its both a number and a digit.
Zero (0) was invented by Aryabhata. The origin of the modern decimal-based place value notation can be traced to the Aryabhatiya ( the only known surviving work of Aryabhata written in 5th century ).