This is the 136th most frequent Norwegian word.
begge
"Begge" means "both" in English.
Here, 'begge' is used to indicate two entities (children) collectively that are performing the action.
Begge barna deltar i skoleprosjektet.
Both children are participating in the school project.
In this sentence, 'begge' functions as a pronoun referring to two unidentified entities that share the same view.
Begge er enige om beslutningen.
Both agree on the decision.
Finally, 'begge' describes the two friends as a pair benefiting from the action in the context of the sentence.