Different sized qr codes
be able to print at least 4 QR codes to a page. Or have them the size of "name tag" Avery sticker labels to stick to the back of other answer methods such as personal white boards.
You can print 4 QR codes to a page by printing the standard set with 2 pages per 8.5 × 11″ sheet. Since each standard page has 2 Plickers QR codes on them, when you print 2 per page, it will automatically have 4 codes per page for you!