The main thing I'm looking for is something that families can do at home easily and without spending money. I know Multiplication by Heart has an online version by Mathigon and Dave Poras just told me there will be one for Addition by Heart as well!

Are they set up to repeat ones they got wrong (I remember in oh, 1998 "Simon Sounds it Out" did that with spelling... )

Card or dice or domino games are amazing and families often have one or more of those tools, right? I am a giant fan of 21 (blackjack), but also addition war (or more). As long as there is a visual (the numbers on the cards, the pips on the dice and the dominos), it can support strategy development.

Where does one find this online Addition by Heart... @davidporas.bsky.social???