Imagine, you are selling chocolate and you sell two different boxes – a larger one and a smaller one. You would like to promote the larger one and stress the difference in size between both boxes to more convincingly justify the higher price for the bigger box.
The smaller box contains 250 grams or 25 units, the larger one has 500 grams or 50 units. How would you state the content of each box? As grams or as units?
You remember an effect called “numerosity effect” which simply means: People conclude from larger numbers a larger magnitude or magnitude difference. Understood – so you settle for grams and believe people likely perceive a difference of 250 grams as larger than 25 units.
Lucky you, you found this Pricing Nugget. Researchers demonstrate that consumers perceive quantities as larger if they can count them – which means discretizing them: Usually, consumers can more easily count units than grams (for example, sugar cubes versus sugar powder).

Hence, consumers perceive a difference between 50 and 25 pieces of chocolate as larger than between 500 grams and 250 grams, despite smaller numbers.
Choose a unit (like cubes of sugar or slices of pizza) that helps customers count (discretize) the content to increase perceived differences between sizes and quantities.
References
Christophe Lembregts, Bram Van Den Bergh (2019), “Making Each Unit Count: The Role of Discretizing Units in Quantity Expressions,” Journal of Consumer Research, 45 (5), 1051–1067.