Lets try to scan multiple IP addresses. For this you need to use this syntax:

nmap 1.1.1.1 8.8.8.8

You can also scan consecutive IP addresses:

nmap -p 1.1.1.1,2,3,4

This will scan 1.1.1.1, 1.1.1.2, 1.1.1.3 and 1.1.1.4.