Note that since we're dealing with 32 numbers, we can count the number of ones from the left and use that as a shorthand for addressing:
255.255.0.0 = /16 255.255.128.0 = /17 255.255.255.0 = /24 255.255.255.128 = /25 255.255.255.192 = /26 255.255.255.224 = /27 255.255.255.240 = /28
