Since 3rd grade math relies on the concepts that were learned during kindergarten, first and second grades, don't be afraid to start your child at a lower level.
Look for games and puzzles that are part of an adaptive learning program. This means that the online games are well-thought out and match the same set of skills that are being taught in the third grade curriculum. The program is structured toward each individual student and fills in the gaps where the child is struggling.
Keep preschool writing activities relaxed and fun. Don't expect or require perfection. Learning to write is a fun process that will give your preschooler a boost in confidence and solid foundation for future studies.
Additional text can be printed as needed or simply read from the computer itself this provides a savings on textbooks and materials for the educator and the student. There will be a substantial savings provided along with the best materials needed.