|Why is that so hard to understand? Think of it in terms of reading/writing one word at a time. In your case, 32-bits. That easily fits in a hundred pins, though I don't remember any memory modules with that pin count.
There were 72-pin SIMMs that handled 32-bit transfers, and that jumped to 168-pin DIMMs with a 64-bit transfer.
Besides power, ground, and control pins, you only need 1 pin per data bit and 1 pin per address line, so it's really not hard to understand.
Anandtech RAM Guide[^]