This is an article we highly recommend you read. Summer boredom can be a great thing for kids. Boredom can actually help a child become more self reliant.
https://qz.com/704723/to-be-more-self-reliant-children-need-boring-summers/
Let them be bored!
Nurturing the whole child
"Glendale Montessori has instilled in my daughters the joy of learning and encouraged them to follow their curiosity to learn more and more. We have been so blessed with wonderful teachers, administration, parent community, etc. that we are hard-pressed to find an equivalent school as our oldest leaves second grade."
- Parent (2009)