Final answer:
Eva and Anna are engaged in cooperative play, as they interact and take turns in a computer game to achieve a common goal.
Step-by-step explanation:
When Eva plays a computer game with Anna, taking turns making the number monster eat a number, they are engaged in cooperative play. Cooperative play is a type of play where children interact with each other to achieve a common goal or to complete a task. In this scenario, Eva and Anna are collaborating and taking turns, which illustrates the key aspects of cooperative play, such as shared decision-making and joint participation.