My kids are 13/11/9/7/3/1 and we homeschool. I took over math in September after the new baby came. I taught the four oldest from the Life of Fred series. The youngest was tearing through the books too fast, so at Christmas I gave her a cribbage board and we played that all spring. Her addition quickly surpassed the 9-year-old, and when we played 3-player together she would tell her sister how to work out things like 16+7.
For multiplication, King Domino is great.
I like that neither game requires reading. Century Spice Road is another one like that we enjoy.
Agricola is bigger and has arithmetic more in the background, but it has a lot of affinity with math. My oldest is decent at it. My youngest aren't competitive at all but they love just collecting big flocks of sheep. You can play without cards (the only reading), but personally I like to deal them a hand and let them ignore them if they like.
Another beautiful no-reading game with less arithmetic but plenty of affinity is Carcassonne.
My kids also get super excited about Robo Rally. It's kind of a programming/planning game. It's way more fun than that turtles game. It starts to bog down past four players though.
So I think one answer to "casual math" is playing games. You're giving them a chance to exercise their brain while having fun (and spending time with you!). No need to mention that it's for the sake of math.
Besides board games there are also puzzles. Just Saturday I brought home some books of brain teasers from Costco. These:
They are much higher-quality than a lot of the math puzzle books out there. So far they seem to be really enjoying them.
For older kids, maybe read a Smullyan book together.
You can also just talk about math a lot, and if you love it you will infect them. One bedtime I explained the Bridges of Königsberg to a then-5-year-old, drawing pictures and letting her try to find a path. Even she could understand a casual proof that only the start & end locations could have an odd number of bridges.
If you tell them about negative/complex numbers a bit too early they feel like you've let them in on a big secret. The fact that high schoolers spend a year studying nothing but triangles blows their mind. I'm sort of notorious for fetching a pencil & paper in the middle of dinner to draw pictures about a thing from geometry/trig/calc/whatever. . . .
For multiplication, King Domino is great.
I like that neither game requires reading. Century Spice Road is another one like that we enjoy.
Agricola is bigger and has arithmetic more in the background, but it has a lot of affinity with math. My oldest is decent at it. My youngest aren't competitive at all but they love just collecting big flocks of sheep. You can play without cards (the only reading), but personally I like to deal them a hand and let them ignore them if they like.
Another beautiful no-reading game with less arithmetic but plenty of affinity is Carcassonne.
My kids also get super excited about Robo Rally. It's kind of a programming/planning game. It's way more fun than that turtles game. It starts to bog down past four players though.
So I think one answer to "casual math" is playing games. You're giving them a chance to exercise their brain while having fun (and spending time with you!). No need to mention that it's for the sake of math.
Besides board games there are also puzzles. Just Saturday I brought home some books of brain teasers from Costco. These:
https://www.amazon.com/Mindworks-Brain-Training-Right-Brain-...
https://www.amazon.com/Mindworks-Training-puzzles-Bind-up-Pa...
They are much higher-quality than a lot of the math puzzle books out there. So far they seem to be really enjoying them.
For older kids, maybe read a Smullyan book together.
You can also just talk about math a lot, and if you love it you will infect them. One bedtime I explained the Bridges of Königsberg to a then-5-year-old, drawing pictures and letting her try to find a path. Even she could understand a casual proof that only the start & end locations could have an odd number of bridges.
If you tell them about negative/complex numbers a bit too early they feel like you've let them in on a big secret. The fact that high schoolers spend a year studying nothing but triangles blows their mind. I'm sort of notorious for fetching a pencil & paper in the middle of dinner to draw pictures about a thing from geometry/trig/calc/whatever. . . .