Although the number system commonly used for counting and measuring is based on the number 10 and is known as the decimal system, there are counting systems based on other numbers. For example, base-2 and base-60 number systems are also used for counting. Base-2, known as the binary number system, is used in electronic computers and other electrical devices. Time on a clock is partially measured in the base-60 system. Each hour is divided into 60 minutes and each minute is divided into 60 seconds. This entry will introduce the base-10 and base-2 number systems.

Base-10 Number System

Because humans have ten fingers, objects are naturally grouped in tens when counting. Counting a dozen apples with one's fingers consists of counting up to ten and then repeating the count, which results in one 10 plus two 1s. So all numbers in this base-10 system are made from just ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

For example...