Snacks packed for sale are displayed in a single portion; however, sometimes they are segregated in separate, smaller portions in a package. Prior research tended to investigate from only one direction and found that segregated objects were perceived as greater than their actual weight. However, few studies have been conducted from the opposing direction to compare single large portion with its segregated, smaller portions and their effect on consumers' purchase intention. The results of this research, consisting of two experiments, show that with a big snack as a referent, the perceived equal amount of small snacks is overestimated, whereas with the small snacks as a referent, the perceived equal amount of the big snack is underestimated. Both perceptual biases are asymmetrical, with the latter more biased than the former. Numerous small portions of snacks have better product evaluation and purchase intention than a single, big snack portion.