Share the Saakhi about Guru Nanak Dev Ji and his three day disappearance with your children. Then children use the re-telling cards to tell the saakhi again in their own words.  
After learnin about Guru Ji's experience and his 3 day disappearance, use the included discussion questions to further drive home his message of Ik Oankar and oneness. 
These activities are meant to be spread over a few days, repeated and discussed. 
Enjoy!