Numbers are shy until you sketch them. With the normal curve, the picture is the plan: mark μ and σ, shade the region, then choose the move… area or cutoff. Most errors aren’t math mistakes; they’re region mistakes. We solve for a left tail when we meant the middle. We read the wrong column. Drawing forces the commitment first and the computation second. It’s the difference between “I think” and “I see.” Grab a pen: draw, shade, label. Then compute what you already decided to find.
