On a rainy day at home, Sophie is flummoxed by a math puzzle using various shapes (tangrams) to make a square, but her sister solves it right away. The next day at school her teacher challenges everyone to exercise their brains (which, she explains, is how brains get stronger, just like muscles) by building a large rectangle out of 12 small squares. Sophie knows before she even begins that it’s useless. “I CAN’T do puzzles and I’m NEVER smart at MATH.” Soon her tablemates all agree: The problem is too hard. “Now’s the time to use the Most Important word,” says their teacher. “That word is YET. You haven’t figured it out … YET.” It turns out there are many ways to solve the problem; Sophie does so by thinking about the rows of vegetables in her garden at home. A note geared toward adults about “growth mindset” follows this story featuring a character who will be familiar to some children (e.g., When Sophie Gets Angry …. Really, Really Angry) in a situation that will be relatable for many. (Ages 4–8)