Recently, I had the opportunity to work with some elementary students on their math fast facts (i.e. single-digit addition, subtraction, multiplication, and division). I noticed that I was able to keep the students much more engaged with one simple change.
Interrupting Visual Engagement
Historically, I would pick up one card at a time and show it to the student. After they answered, I would put it down and pickup the next card.
This is the style Bill Murray uses in the opening scene of Ghostbusters.
I found this created down time between each card, where the student was not visually engaged.
Uninterrupted Visual Engagement
By instead holding the entire pack of cards facing the student and then removing the top card after they answer it, the next card is immediately visually accessible. Anecdotally, I found this significantly increased the speed of the students answering the questions.
Many flashcard packs include the answers on the back of the flash cards. Unfortunately, this technique does prevent viewing these answers. I addressed this by sitting so both the student and I could see the front of the cards (and I knew the answers to these questions). I could imagine designing flashcards so the answer appeared on the back of the cards at the top, then one could shift the top card up to view it (or the entire pack could be held with each card staggered slightly lower than the card behind it).