# Decagram

A decagram (dag), also spelled dekagram, is a unit of weight in the metric system of measurement.

1 decagram = 0.01 kilograms

1 decagram = 10 grams

Below are some relationships between decagrams and units of mass in the US customary system of measurement.

1 decagram = 0.022 pounds

1 decagram = 0.353 ounces

The decagram is not a widely used unit of mass. It is relatively close in magnitude to the kilogram, the SI base unit, and therefore standard unit of mass used throughout most of the world. Even within the US, which uses the US customary system for most everyday measurements, the kilogram is widely used in industry, research, the military, and more. Because decagrams and kilograms are relatively close in magnitude, there is little reason to use decagrams unless a high degree of precision, such as in a laboratory setting, is necessary.

## SI prefixes

The International System of Units (SI) makes use of SI prefixes (milli-, centi-, kilo-, deca-, etc.) to denote multiples or submultiples of a base unit that are related by a power of 10. The base unit of mass in SI is the kilogram. The kilogram is unique as a base unit in that it is the only base unit that already has an SI prefix, kilo-, indicating that 1 kilogram is 10^{3} grams. All other base units in SI such as meters, seconds, moles, etc., do not have prefixes.

Since SI does not allow for the use of multiple prefixes (e.g. "kilomilligram") to modify a base unit, prefixes are added to the gram, rather than kilogram, to denote different multiples or submultiples of mass.

1 decagram = 10^{-2} kilograms

1 decagram = 10^{1} grams

1 decagram = 10^{3} centigrams

1 decagram = 10^{4} milligrams

Remembering SI prefixes and what power of 10 they represent is helpful because it allows us to choose the most appropriate unit for whatever is being measured. For example, a clove of garlic may weigh 2 decagrams. A 2 decagram clove of garlic has a mass of 20,000 milligrams. While this value may still be relatively simple to work with when making calculations, it is still more tedious than working with a value of 2 decagrams.

It is also important to be able to convert between various measurements of mass in different systems, particularly from US customary units to SI, since SI is the standard used throughout most of the world.

Examples

Convert the following measurements to decagrams and kilograms.

1. 77 pounds:

There are 0.022 pounds in 1 decagram, or 45.359 decagrams in 1 pound, so:

77 × 45.359 = 3,492.643 dag

3,492.643 × 10^{-2} = 34.927 kg

2. 20 ounces:

There are 0.353 ounces in 1 decagram, or 2.835 decagrams in 1 ounce, so:

20 × 2.835 = 56.7 dag

56.7 × 10^{-2} = 0.567 kg