You often have to make quick judgments about the number of objects you encounter in the world. You might see a group of people walking toward you. It is useful to know whether there are roughly five, ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Hello! Today we are learning how to use numbers to count a collection of objects. Let's try seven. When ...

Humans and animals have a "number sense," an inborn ability to register the number of objects in a scene. The neural basis of this ability is believed to be what are called the number neurons, which ...

Is it possible to count objects you can't see? If you've ever received a boxed gift, or a mysterious package from Amazon, you might have tried to lightly shake the box to try to guess its contents.