The mechanics of this lesson (using cards that are either UP or DOWN) lends itself to a neat physical binary activity that might be worth trying somewhere in the lesson…
You can group students into 4’s and have them sit in a row with each person holding one of the number cards. Then display a base-10 number for all the groups to see and each group has to determine how to represent that number in binary (ie: 10 = 1010). But, instead of flipping cards Up for 1 and Down for 0: students stand for 1 or stay sitting for 0. It basically accomplishes the same thing as the cards, but there’s a kinesthetic/movement dynamic to this activity that can be fun, and students tend to get competitive. It’s also easy to scale - combine two groups of 4 into a group of 8 and see if they can figure out how to represent 8-bit binary numbers - and it can last a while in case the lesson runs a little short.