Please how many IPs is when i add /24 after an IP address?
how big is a /24 ip range ?

Example:
212.185.44.1/24
(i want to block all numbers in 4th octet , 4th number (1-255))


Update: i think when one want to block all IP numbers like 1.2.3.* (all numbers instead of *)
one should block /24 (1.2.3.0/24)