I found the below activity on TeachStarter and believe it would be an appropriate option for year 3-5 students who are bing introduced to binary data. In the activity, the students are provided with the worksheet in which they are required to translate their date of birth (ie – 01/01/2010) into the binary data representation.

Once the students have represented their own birthday in Binary form, they would swap with a friend or form small groups to translate the birthday’s of their friends (both into the binary representation and vice versa).

https://www.teachstarter.com/au/teaching-resource/make-binary-code-birthday-card-activity/