Decimal numeration system

The decimal numeration system is a system for expressing the value of numbers based on grouping by tens.

Each place in the decimal numeration system has a value that is a power of 10. The "Whole Numbers" chart, shown below, can be continued to the left for writing whole numbers larger than billions.

Similarly, the chart "Decimal Fractions" can be continued to the right for writing decimal fractions smaller than millionths.

Also called base-ten numeration system, Hindu-Arabic numeration system.

See also decimal fraction, place value.