diff --git a/sasdata/quantities/_build_tables.py b/sasdata/quantities/_build_tables.py
index c07497471..ba07aee80 100644
--- a/sasdata/quantities/_build_tables.py
+++ b/sasdata/quantities/_build_tables.py
@@ -68,6 +68,7 @@
     UnitData("y", None, None, "year", "years", 3600*24*365.2425, 0, 1, 0, 0, 0, 0, 0, []),
     UnitData("deg", None, None, "degree", "degrees", 180/np.pi, 0, 0, 0, 0, 0, 0, 1, []),
     UnitData("rad", None, None, "radian", "radians", 1, 0, 0, 0, 0, 0, 0, 1, []),
+    UnitData("rot", None, None, "rotation", "rotations", 2*np.pi, 0, 0, 0, 0, 0, 0, 1, []),
     UnitData("sr", None, None, "stradian", "stradians", 1, 0, 0, 0, 0, 0, 0, 2, []),
     UnitData("l", None, None, "litre", "litres", 1e-3, 3, 0, 0, 0, 0, 0, 0, []),
     UnitData("eV", None, None, "electronvolt", "electronvolts", 1.602176634e-19, 2, -2, 1, 0, 0, 0, 0, all_magnitudes),
diff --git a/sasdata/quantities/_units_base.py b/sasdata/quantities/_units_base.py
index 17897f895..9e6401b53 100644
--- a/sasdata/quantities/_units_base.py
+++ b/sasdata/quantities/_units_base.py
@@ -214,17 +214,20 @@ def _components(self, tokens: Sequence["UnitToken"]):
         pass
 
     def __mul__(self: Self, other: "Unit"):
-        if not isinstance(other, Unit):
-            return NotImplemented
-
-        return Unit(self.scale * other.scale, self.dimensions * other.dimensions)
+        if isinstance(other, Unit):
+            return Unit(self.scale * other.scale, self.dimensions * other.dimensions)
+        elif isinstance(other, (int, float)):
+            return Unit(other * self.scale, self.dimensions)
+        return NotImplemented
 
     def __truediv__(self: Self, other: "Unit"):
-        if not isinstance(other, Unit):
+        if isinstance(other, Unit):
+            return Unit(self.scale / other.scale, self.dimensions / other.dimensions)
+        elif isinstance(other, (int, float)):
+            return Unit(self.scale / other, self.dimensions)
+        else:
             return NotImplemented
 
-        return Unit(self.scale / other.scale, self.dimensions / other.dimensions)
-
     def __rtruediv__(self: Self, other: "Unit"):
         if isinstance(other, Unit):
             return Unit(other.scale / self.scale, other.dimensions / self.dimensions)
diff --git a/sasdata/quantities/units.py b/sasdata/quantities/units.py
index 8af224043..7d03abda0 100644
--- a/sasdata/quantities/units.py
+++ b/sasdata/quantities/units.py
@@ -299,17 +299,20 @@ def _components(self, tokens: Sequence["UnitToken"]):
         pass
 
     def __mul__(self: Self, other: "Unit"):
-        if not isinstance(other, Unit):
-            return NotImplemented
-
-        return Unit(self.scale * other.scale, self.dimensions * other.dimensions)
+        if isinstance(other, Unit):
+            return Unit(self.scale * other.scale, self.dimensions * other.dimensions)
+        elif isinstance(other, (int, float)):
+            return Unit(other * self.scale, self.dimensions)
+        return NotImplemented
 
     def __truediv__(self: Self, other: "Unit"):
-        if not isinstance(other, Unit):
+        if isinstance(other, Unit):
+            return Unit(self.scale / other.scale, self.dimensions / other.dimensions)
+        elif isinstance(other, (int, float)):
+            return Unit(self.scale / other, self.dimensions)
+        else:
             return NotImplemented
 
-        return Unit(self.scale / other.scale, self.dimensions / other.dimensions)
-
     def __rtruediv__(self: Self, other: "Unit"):
         if isinstance(other, Unit):
             return Unit(other.scale / self.scale, other.dimensions / self.dimensions)
@@ -692,6 +695,7 @@ def __init__(self, name: str, units: list[NamedUnit]):
 years = NamedUnit(31556952.0, Dimensions(0, 1, 0, 0, 0, 0, 0),name='years',ascii_symbol='y',symbol='y')
 degrees = NamedUnit(57.29577951308232, Dimensions(0, 0, 0, 0, 0, 0, 1),name='degrees',ascii_symbol='deg',symbol='deg')
 radians = NamedUnit(1, Dimensions(0, 0, 0, 0, 0, 0, 1),name='radians',ascii_symbol='rad',symbol='rad')
+rotations = NamedUnit(6.283185307179586, Dimensions(0, 0, 0, 0, 0, 0, 1),name='rotations',ascii_symbol='rot',symbol='rot')
 stradians = NamedUnit(1, Dimensions(0, 0, 0, 0, 0, 0, 2),name='stradians',ascii_symbol='sr',symbol='sr')
 litres = NamedUnit(0.001, Dimensions(3, 0, 0, 0, 0, 0, 0),name='litres',ascii_symbol='l',symbol='l')
 electronvolts = NamedUnit(1.602176634e-19, Dimensions(2, -2, 1, 0, 0, 0, 0),name='electronvolts',ascii_symbol='eV',symbol='eV')
@@ -2052,6 +2056,7 @@ def __init__(self, name: str, units: list[NamedUnit]):
         "y": years,
         "deg": degrees,
         "rad": radians,
+        "rot": rotations,
         "sr": stradians,
         "l": litres,
         "eV": electronvolts,
@@ -3385,6 +3390,7 @@ def __init__(self, name: str, units: list[NamedUnit]):
   units = [
     degrees,
     radians,
+    rotations,
 ])
 
 solid_angle = UnitGroup(
diff --git a/test/quantities/utest_units.py b/test/quantities/utest_units.py
index 258143e2a..3bc775313 100644
--- a/test/quantities/utest_units.py
+++ b/test/quantities/utest_units.py
@@ -1,3 +1,5 @@
+import math
+
 import sasdata.quantities.units as units
 from sasdata.quantities.units import Unit
 
@@ -9,7 +11,7 @@ def __init__(self, test_name: str, *units):
 
     def run_test(self):
         for i, unit_1 in enumerate(self.units):
-            for unit_2 in self.units[i+1:]:
+            for unit_2 in self.units[i + 1 :]:
                 assert unit_1.equivalent(unit_2), "Units should be equivalent"
                 assert unit_1 == unit_2, "Units should be equal"
 
@@ -21,11 +23,22 @@ def __init__(self, test_name: str, *units):
 
     def run_test(self):
         for i, unit_1 in enumerate(self.units):
-            for unit_2 in self.units[i+1:]:
+            for unit_2 in self.units[i + 1 :]:
                 assert unit_1.equivalent(unit_2), "Units should be equivalent"
                 assert unit_1 != unit_2, "Units should not be equal"
 
 
+class DissimilarUnits:
+    def __init__(self, test_name: str, *units):
+        self.test_name = "Dissimilar: " + test_name
+        self.units: list[Unit] = list(units)
+
+    def run_test(self):
+        for i, unit_1 in enumerate(self.units):
+            for unit_2 in self.units[i + 1 :]:
+                assert not unit_1.equivalent(unit_2), "Units should not be equivalent"
+
+
 tests = [
 
     EqualUnits("Pressure",
@@ -36,7 +49,19 @@ def run_test(self):
     EqualUnits("Resistance",
                units.ohms,
                units.volts / units.amperes,
-               1e-3/units.millisiemens)
+               1e-3/units.millisiemens),
+
+    EquivalentButUnequalUnits("Angular frequency",
+               units.rotations / units.minutes,
+               units.degrees * units.hertz),
+
+    EqualUnits("Angular frequency",
+               (units.rotations/units.minutes ),
+               (units.radians*units.hertz) * 2 * math.pi/60.0),
+
+    DissimilarUnits("Frequency and Angular frequency",
+                    (units.rotations/units.minutes),
+                    (units.hertz)),
 
 
 ]