CIDR stands for Classless Inter Domain Routing. CIDR block is used to define a range of IP addresses. CIDR notation is composed of an IP address followed by a slash and a number called the network prefix. To get the number of IP adresses of your CIDR block, please give the prefix number after the slash of your CIDR block, for example: slash 16.
“Alexa, ask CIDR block what's the number of hosts for slash 16”