Base ten, also known as the decimal system, is a number system that uses ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. Each digit's position in a number represents a power of ten. For example, in the number 345, the digit 3 represents three hundreds, the digit 4 represents four tens, and the digit 5 represents five units. This system is widely used in everyday counting and calculations. It is intuitive because humans typically have ten fingers, making it a natural choice for representing quantities. Other number systems, like binary or hexadecimal, use different bases, but base ten remains the most common.