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.
There are three rules on determining how many significant figures are in a number: 1  Non-zero digits are always significant. 2  Any zeros between two significant digits are significant. 3  A final zero or trailing zeros in the decimal portion ONLY are significant.