Although we no longer use the English From the Roots Up curriculum since we switched to a full-blown Latin program (Latina Christiana I), I still have the computer file I made to print my own flashcards for use with the EFTRU curriculum. I had two kids and 100 cards each to make, so I thought printing them out would be much easier (and it was!). I thought I'd post the .pdf file here in case others can use it. Just click on the link to download it.
The .pdf file consists of 100 pages, one page for each root card in English From the Roots Up (Volume 1). The file prints only the root on the card; the back of the card, with all the derivatives, will still need to be filled out by the student. When I printed out my cards, I simply fed a 4×6 index card into my printer one at a time. (I printed the root on the blank side and left the ruled side for the kids to write on.) After the card printed, I used a green and red marker to mark the edges of the cards as the curriculum directed (red for Latin roots and green for Greek roots). Enjoy!