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3 System of Units
Table 3.4 Basic roules for
writing symbols and unit’s
name
The symbols and unit names should not be combined in the
record
Correct
Incorrect
10 g/kg or 10 g • kg −1
10 g per kilogram
10 grams per kilogram
10 grams per kg
Table 3.5 Basic roules for
writing units with a numerical
values
Assigning units to a numerical value should be unequivocal
Correct
Incorrect
35 g × 48 g
35 × 48 g
100 g ± 2 g
100 ± 2 g
(100 ± 2) g
– The quantity of the measured mass is marked with the symbol (m), a unit of mass
is the kilogram, and a symbol is a unit of mass (kg).
– The quantity of the measured length is marked with the symbol (l), the unit of
length is the meter, a unit symbol of length is (m). The symbols and unit names
should not be combined (Table 3.4).
3.3 Editorial Requirements with Regard to Writing SI
Units
– The designation of the symbol of unit remains unchanged in the plural (we do not
add the plural suffix);
– After designating the unit (symbol) we do not add a full stop to indicate a contraction; unless it is the end of the sentence;
– Complex units, created by the multiplication of several units must be written as
follows: e.g., Nm, N m, N • m, N × m;
– Complex units, created by dividing of several units must be written as follows:
e.g., m/s or m s
−1 ;
– Designations of units must be separated by a space from the numeric value, e.g.,
8 kg and not 8 kg;
– Assigning units to a numerical value should be unequivocal (see Table 3.5).
The prefix symbol is placed before the symbol of the unit, without a space; for
example, μg, not μ g.