Title: Base unit (measurement)
Content:  In the International System of Units, there are seven base units: kilogram, metre, candela, second, ampere, kelvin, and mole.
Title: International System of Units
Content:  The International System of Units consists of a set of base units, derived units, and a set of decimal-based multipliers that are used as prefixes. The units, excluding prefixed units, form a coherent system of units, which is based on a system of quantities in such a way that the equations between the numerical values expressed in coherent units have exactly the same form, including numerical factors, as the corresponding equations between the quantities. For example, 1 N = 1 kg × 1 m/s2 says that one newton is the force required to accelerate a mass of one kilogram at one metre per second squared, as related through the principle of coherence to the equation relating 
Title: Unit of measurement
Content:  each other exposed many inconsistencies, and brought about the development of new units and systems. The system of units varies from country to country and some of the different system of units are CGS system of units, FPS system of units, MKS system of units and SI system of units. Among the different system of units using in the world, the most widely used and internationally accepted one is the International System of Units, or SI system of units. In this SI units system, there are seven SI base units and three supplementary units. The base SI units are metre, kilogram, second, kelvin, ampere, candela and the mole and the three supplementary SI units are radian, steradian and becquerel. All other SI units can be derived from these base units. Systems of measurement in modern use include the metric system, the imperial system, and United States customary units.
Title: Measurement
Content:  The International System of Units (abbreviated as SI from the French language name Système International d'Unités) is the modern revision of the metric system. It is the world's most widely used system of units, both in everyday commerce and in science. The SI was developed in 1960 from the metre–kilogram–second (MKS) system, rather than the centimetre–gram–second (CGS) system, which, in turn, had many variants. The SI units for the seven base physical quantities are: In the SI, base units are the simple measurements for time, length, mass, temperature, amount of substance, electric current and light intensity. Derived units are constructed from the base units, for example, the watt, i.e. the unit for power, is defined from the base units as m2·kg·s−3. Other physical properties may be measured in compound units, such as material density, measured in kg/m3.
Title: Metric system
Content:  of the International System of Units (SI), the seven base units are: metre for length, kilogram for mass, second for time, ampere for electric current, kelvin for temperature, candela for luminous intensity and mole for amount of substance. These, together with their derived units, can measure any physical quantity. Derived units may have their own unit name, such as the watt (J/s) and lux (cd/m2), or may just be expressed as combinations of base units, such as velocity (m/s) and acceleration (m/s2). The metric system was designed to have properties that make it easy to use and widely applicable, including units 
Title: SI base unit
Content:  [[File:SI base units.svg|thumb|right|264px| The seven SI base units ]]The SI base units are the standard units of measurement defined by the International System of Units (SI) for the seven base quantities of what is now known as the International System of Quantities: they are notably a basic set from which all other SI units can be derived. The units and their physical quantities are the second for time, the metre for length, the kilogram for mass, the ampere for electric current, the kelvin for thermodynamic temperature, the mole for amount of substance, and the candela for luminous intensity. The SI base units are a fundamental part of modern metrology, and thus part of the foundation 
Title: Metrology
Content:  The International System of Units (SI) defines seven base units: length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity. By convention, each of these units are considered to be mutually independent of each other and can be constructed directly from the defining constants. All other SI units are constructed as products of powers of the seven base units. Since the base units are the reference points for all measurements taken in SI units, if the reference value changed all prior measurements would be incorrect. Before 2019, if a piece of the international prototype of the kilogram had been snapped off, it would have still been defined as a kilogram; all previous measured values of a kilogram would be heavier. The importance of reproducible SI units has led the BIPM to complete the task of defining all SI base units in terms 
Title: International System of Units
Content:  The SI selects seven units to serve as base units, corresponding to seven base physical quantities. They are the second, with the symbol s, which is the SI unit of the physical quantity of time; the metre, symbol  m, the SI unit of length; kilogram ( kg, the unit of mass); ampere ( A, electric current); kelvin ( K, thermodynamic temperature); mole ( mol, amount of substance); and candela ( cd, luminous intensity). All units in the SI can be expressed in terms of the base units, and the base units serve as a preferred set for expressing or analysing the relationships between units.
Title: Base unit (measurement)
Content:  A base unit (also referred to as a fundamental unit) is a unit adopted for measurement of a base quantity. A base quantity is one of a conventionally chosen subset of physical quantities, where no quantity in the subset can be expressed in terms of the others. The SI units, or Systeme International d'unites which consists of the metre, kilogram, second, ampere, Kelvin, mole and candela are base units. A base unit is one that has been explicitly so designated; a secondary unit for the same quantity is a derived unit. For example, when used with the International System of Units, the gram is a derived unit, not a base 
Title: International System of Units
Content:   The International System of Units, known by the international abbreviation SI in all languages   and sometimes pleonastically as the SI system, is the modern form  :41 of the metric system and the world's most widely used system of measurement. :252 Established and maintained by the General Conference on Weights and Measures (CGPM), it is the only system of measurement with an official status in nearly every country in the world, employed in science, technology, industry, and everyday commerce. The SI comprises a coherent system of units of measurement starting with seven base units, which are the second (symbol s, the unit of time), metre (m, length), kilogram (kg, mass), ampere (A, 

Question: what is the number of basic units in the international system of units?
Answer: seven.