3.72x10^3 kg is 3.72x10^6 g. Since the metric system is in a base of ten conversions are simply a matter of adding or taking away zeroes. AnswerParty!
Systems of units
Units of mass
A system of measurement is a set of units which can be used to specify anything which can be measured and were historically important, regulated and defined because of trade and internal commerce. In modern systems of measurement, some quantities are designated as fundamental units, meaning all other needed units can be derived from them, whereas in the early and most historic eras, the units were given by fiat (see statutory law) by the ruling entities and were not necessarily well inter-related or self-consistent.
In physics, mass (from Greek μᾶζα "barley cake, lump [of dough]") is a property of a physical system or body, giving rise to the phenomena of the body's resistance to being accelerated by a force and the strength of its mutual gravitational attraction with other bodies. Instruments such as mass balances or scales use those phenomena to measure mass. The SI unit of mass is the kilogram (kg).
For everyday objects and energies well-described by Newtonian physics, mass has also been said to represent an amount of matter, but this view breaks down, for example, at very high speeds or for subatomic particles. Holding true more generally, any body having mass has an equivalent amount of energy, and all forms of energy resist acceleration by a force and have gravitational attraction; the term matter has no universally-agreed definition under this modern view.
International System of Units
The metric system is an internationally agreed decimal system of measurement that was originally based on the mètre des Archives and the kilogramme des Archives introduced by France in 1799. Over the years, the definitions of the metre and kilogram have been refined and the metric system has been extended to incorporate many more units. Although a number of variants of the metric system emerged in the late nineteenth and early twentieth centuries, the term is now often used as a synonym for "SI" or the "International System of Units"—the official system of measurement in almost every country in the world.
The metric system has been officially sanctioned for use in the United States since 1866, but it remains the only industrialised country that has not adopted the metric system as its official system of measurement. Many sources also cite Liberia and Burma as the only other countries not to have done so. Although the United Kingdom uses the metric system for most official purposes, the use of the imperial system of measure, particularly in unregulated sectors such as journalism, is widespread.
The International System of Units (abbreviated SI from French: Le Système international d'unités) is the modern form of the metric system and is the world's most widely used system of measurement, used in both everyday commerce and science. It comprises a coherent system of units of measurement built around seven base units, 22 named and an indeterminate number of unnamed coherent derived units, and a set of prefixes that act as decimal-based multipliers.
The standards, published in 1960 as the result of an initiative started in 1948, are based on the metre–kilogram–second (MKS) system, rather than the centimetre–gram–second (CGS) system, which, in turn, had several variants. The SI has been declared to be an evolving system; thus prefixes and units are created and unit definitions are modified through international agreement as the technology of measurement progresses, and as the precision of measurements improves.