The following crypto-families are based on the Virginia Standards of Learning. Each group, or family, is made up of vocabulary words taken from each of the nine, fourth grade science units.
I created these worksheets with both fourth and fifth grade students in mind. Fourth grade teachers can use the applicable worksheets while teaching each unit. Fifth grade teachers can use them through-out the school year or as they review for the fifth grade science SOL, which unfortunately includes fourth grade science information.
These worksheets would even work well for states, counties, or schools that don't use the Virginia Standards of Learning. Since each family of words is based on an individual theme, students will still be able to break each code and discover the related words.