By the Digits is a fully interactive activity to teach your students about place value, regrouping, addition and estimation. Simply tap the "round" number and a random number will appear in the "digit" column. Write that digit in the ones or tens place. Continue for 7 rounds, add up the ones and tens and see how close to 100 you got.
This comes in a "demo" version, which is a single board, and a "competition version" where two teams can compete against one another (mad shoutout to Karol who suggested this!)
Great practice & strategy game!