Reply To: Materials for Lessons A-1 to A-9
Hands-on lessons are especially developed so that things you need will be items you probably have around the house or can easily purchase at a supermarket of office supply store. (Peruse the lists given here.) When you get to Volume II, a microscope and balance will be required. (see specifications in Volume II, 2 ed, Appendix 5 (page 435).
Lessons in Volumes II and III build on what is presented in Volume I. Therefore, I recommend that all your kids start with Volume I. Older kids can go much more deeply while younger ones still get the concept.