Caption: Unit conversion.

Unit conversions often seem difficult,
but they are simple with the general approach of using
factors of unity (i.e., conversion factors)
which are
factors that
have value 1.
The key point is that multiplication
by a
factor of unity
does **NOT** change the value of thing it multiplies because
the factor of unity
has value 1.

One does unit conversions by multiplying numbers by factors of unity and treating units as algebraic symbols (or algebraic variables) which is correct since units are algebraic symbols among other things.

For example, say you wanted to convert 10 km into meters. Well 1 km = 10**3 m. Therefore, the appropriate factors of unity is 1 = (10**3 m/1 km). Thus

10 km = 10 km * 1 = 10 km * (10**3 m/1 km) = 10**4 m .The example above, generalizes to all other cases straightforwardly---'nuff said.

Credit/Permission:
Credit/Permission: ©
David Jeffery,
2016 / Own work.

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