Helping students to develop math fluency takes more than just flash cards. It requires teaching them how to think about numbers. And while that may seem daunting, most kids enjoy sharpening their math ...

The 80/20 rule dictates that your stuff should take up only 80 percent of a given space — a closet, a drawer, a bookshelf — leaving 20 percent empty. Think of it as headroom for your stuff: Leaving ...