Mental arithmetic at the dinner table. It turns out that the 7yo can add and multiply two-digit numbers, which I think I knew but had been doubting since yesterday, and add fractions, and the 5yo can add single-digit numbers if the 7yo shuts up long enough to let her get an answer in edgeways.
I’m not at all sure why the 7yo hates writing down anything to do with arithmetic but if her mental arithmetic can carry her this far I’m sure it’ll all be fine. She’s pretty good at knowing roughly where the answer needs to be, too – if the 5yo guesses “a hundred!” while the 7yo is doing a calculation, she says “No, silly, it’s [bigger|smaller] than that!” long before she’s reached the actual answer.
Right path, I’d say. Fractions all boil down to cake, too.