AdministratorMay 23, 2020 at 9:48 pm
Exploding dots are great! Explodingdots.org
As for where we need to focus on place value… I think that while it’d be great if students had a firm conceptual grasp by middle school, the reality is many do not. So, in that world, I’d argue we still need to pay attention to this big idea and continue bringing it back to the forefront!