Alejandro is eating Cheerios. His mother gives him a bowl of 8 cheerios. She makes herself a bowl of 20 cheerios. Alejandro immediately cries because he recognizes Mom has more. This relies on which core knowledge system?

Countable and or numerable items set core knowledge systems

Explanation:

Core knowledge systems includes; a) Geometry and spatial systems, b) Countable items sets systems, c) Inanimate object knowledge system, d) Animate agents or creatures e) Social identification and interaction

Within the countable items, number set knowledge system are three principles including the reduction of accuracy as the number values increases, same disposition to items that are being counted, arithmetic sensibilities

Given that Alejandro is able to recognize that the sum of the cheerios he has is less than the sum of cheerios his mom has, it is related to the countable items set system, and Alejandro is displaying arithmetic sensibilities