If you mean for cookies and brownies you have to consider that they usually make an enitre batch, so in the end there are several cookies and brownies and it requires a good amount of cannabis to have each individual cookie/brownie give desired effects.
If only four people want to eat weed, I suggest a gram each of good bud for a nice long trip. You can make cannabutter and spread it onto some bread or firecrackers. (Look at previous threads)