Yeast

I’m going to do some 1 gallon batches using different styles of yeast. If I use smack packs, how much should I put in a 1 gallon batch? If I don’t use a full pack, can I safely save the rest in sterilized jar for future use? Thanks in advance!

Sure you can save the rest.
As for how much to use it depends on the OG of the brew, but since it’s probably average, I’d just use something like 1/3 pack.