Samantha,
One module covers 1 year. I’m not sure what they’ve covered before, but if you chose Module 1, you would spend one year there (approx) w/ each child in their appropriate level. Next year, you would cover Module 2 w/ everyone, etc…
You would just read the books in grade 1-3 to those in 1-3 grades and books for 1-6 to those in 4-6.
I know this is short, but maybe it’ll get you started.
Blessings,
Christie