I have a headcanon that Hermione insists her children attend some primary muggle schooling before Hogwarts, just as she had done. Now, imagine Arthur Weasley attending his grandchild’s science fair, being the ultra proud grandfather….and yet also completely geeking out over absolutely EVERYTHING.
Canon
“That is a volcano, that is a VERY SMALL VOLCANO, how - young lady, how did you make this? Baking soda and food coloring? MARVELOUS!”
the kids would love him.
Never have I ever loved anything more than I love this
All the muggle teachers would think he was being so adorable, “pretending” not to know how potato batteries and mini-volcanoes work, fawning over the hard work the kids did on even the simplest the projects. And he comes every year, because after the kids have aged out (”gone on to some boarding school in Scotland,” the teachers say over bad coffee in the break room, “they didn’t seem the type”), he gets an honorary invitation to the fair every year, because he never stops making the kids feel smart and good.