times another, the former quantity is said to be three orders of magnitude greater than the latter. [P1.1]
is: an approximation to the value of a quantity which rounds the value up or down to the nearest integer power of ten. For example, if one quantity is roughly times another, the former quantity is said to be three orders of magnitude greater than the latter. [P1.1]
is symbolized: by ~, which may be read as 'has the order of magnitude'. For example 
and 
[M1.2]
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