Parent involvement can be a challenging task. One way you may be able to incoorporate parent involvement is by asking for parent volunteers to help with experiements or projects in the classroom. This is a way to share with parents what their child is doing in the classroom while also getting them engaged in their child's learning. I also think it is important to take into consideration parents jobs. Each parent may be able to come in and share something with the class that could be benifical to their learning and it could apply to the curriculum. If a parent was in the medical profession it would be easy to relate it to a science standard. The parent, with any profession, could dicuss how they use math, reading, and writing throughout their work day to demostrate how important each subject is.
I hope this gives you some ideas!