Some people prefer to use bound books, while others want the pages in looseleaf format (which can be done by cutting apart a bound book or printing from PDF files). Sometimes, the decisive factor is cost-saving. International customers usually find that printing is a much less expensive than paying for shipping.
Increasingly, parents and teachers are comfortable teaching from a laptop or tablet, so the PDF works fine for them, and saves a little money, too.
In most of our curriculum, the student uses all the workbook pages...but with a PDF, you can print as you go, which maximized storage space. For The Story of the World Student Pages or Coloring Pages, the student will probably use only a portion of the pages; these can be printed as needed, and for as many students as are in the home.
If you wish to compare the cost of buying pre-printed books with printing PDF files do the math and compare the results:
- Physical materials cost = price of the book + shipping.
- Printing of PDF cost = price of the PDF + (cost of printing per page x number of pages to be printed) + cost of binding (if any).
Copy centers charge different rates per page, so check with a couple of vendors to confirm their rates.
Except for the Math With Confidence and Math Facts That Stick series, all the pages are black-and-white. The math materials can be printed in black and white (grayscale) to save a little money, but it is less attractive and less appealing for the young student.