Making Sense of Adding on an Open Number Line
If you've ever watched a student struggle with the "old school" way of carrying digits, you'll quickly see why adding on an open number line is such a game-changer for building real number sense. It's one of those tools that looks a bit strange at first if you grew up doing vertical addition, but once it clicks, it's like a lightbulb goes off. Instead of just memorizing steps, you're actually visualizing the "distance" between numbers and how they grow. ...