Final answer:
The number of days between February 11, 2019, to September 3, 2019, is 215 days.
Step-by-step explanation:
To find the number of days between February 11, 2019, and September 3, 2019, we need to count the number of days in each of the months between these two dates. From February 11 to the end of February, there are 28 days. In March, there are 31 days. In April, there are 30 days. In May, there are 31 days. In June, there are 30 days. In July, there are 31 days. In August, there are 31 days, and finally, in September, there are 3 days. Adding all of these together, we get a total of 215 days.