If you’ve ever played peekaboo with your little one, you’ve helped them work on object permanence. Your baby is learning that people and objects exist even when they can’t see or hear them. Object ...

How I rapidly generate thousands of tests to catch stealthy bugs ...

Two-dimensional (2D) shapes are completely flat. They cannot be picked up. 2D shapes can be found printed in a book or you can draw them on a piece of paper. 2D shapes have sides and corners (also ...