diff --git a/manim/mobject/graphing/number_line.py b/manim/mobject/graphing/number_line.py
index 017fac5bcb..769760d2e9 100644
--- a/manim/mobject/graphing/number_line.py
+++ b/manim/mobject/graphing/number_line.py
@@ -12,6 +12,8 @@
 from typing import TYPE_CHECKING, Callable
 
 if TYPE_CHECKING:
+    from typing_extensions import Self
+
     from manim.mobject.geometry.tips import ArrowTip
     from manim.typing import Point3DLike
 
@@ -485,25 +487,22 @@ def get_number_mobject(
             num_mob.shift(num_mob[0].width * LEFT / 2)
         return num_mob
 
-    def get_number_mobjects(self, *numbers, **kwargs) -> VGroup:
-        if len(numbers) == 0:
-            numbers = self.default_numbers_to_display()
+    def get_number_mobjects(
+        self, numbers: Iterable[float] | None = None, **kwargs
+    ) -> VGroup:
+        if numbers is None:
+            numbers = self.get_numbers_to_display()
         return VGroup([self.get_number_mobject(number, **kwargs) for number in numbers])
 
     def get_labels(self) -> VGroup:
         return self.get_number_mobjects()
 
-    def add_numbers(
+    def get_numbers_to_display(
         self,
         x_values: Iterable[float] | None = None,
         excluding: Iterable[float] | None = None,
-        font_size: float | None = None,
-        label_constructor: VMobject | None = None,
-        **kwargs,
-    ):
-        """Adds :class:`~.DecimalNumber` mobjects representing their position
-        at each tick of the number line. The numbers can be accessed after creation
-        via ``self.numbers``.
+    ) -> list[float]:
+        """Returns a list of numbers to be labeled on the number line.
 
         Parameters
         ----------
@@ -512,13 +511,11 @@ def add_numbers(
             Defaults to the output produced by :meth:`~.NumberLine.get_tick_range`
         excluding
             A list of values to exclude from :attr:`x_values`.
-        font_size
-            The font size of the labels. Defaults to the ``font_size`` attribute
-            of the number line.
-        label_constructor
-            The :class:`~.VMobject` class that will be used to construct the label.
-            Defaults to the ``label_constructor`` attribute of the number line
-            if not specified.
+
+        Returns
+        -------
+        list[float]
+            The list of numbers to be labeled on the number line.
         """
         if x_values is None:
             x_values = self.get_tick_range()
@@ -526,24 +523,30 @@ def add_numbers(
         if excluding is None:
             excluding = self.numbers_to_exclude
 
-        if font_size is None:
-            font_size = self.font_size
+        return [x for x in x_values if x not in excluding]
 
-        if label_constructor is None:
-            label_constructor = self.label_constructor
+    def add_numbers(
+        self,
+        x_values: Iterable[float] | None = None,
+        excluding: Iterable[float] | None = None,
+        **kwargs,
+    ) -> Self:
+        """Adds :class:`~.DecimalNumber` mobjects representing their position
+        at each tick of the number line. The numbers can be accessed after creation
+        via ``self.numbers``.
 
-        numbers = VGroup()
-        for x in x_values:
-            if x in excluding:
-                continue
-            numbers.add(
-                self.get_number_mobject(
-                    x,
-                    font_size=font_size,
-                    label_constructor=label_constructor,
-                    **kwargs,
-                )
-            )
+        Parameters
+        ----------
+        x_values
+            An iterable of the values used to position and create the labels.
+            Defaults to the output produced by :meth:`~.NumberLine.get_tick_range`
+        excluding
+            A list of values to exclude from :attr:`x_values`.
+        **kwargs
+            The keyword arguments passed to :meth:`get_number_mobject`
+        """
+        numbers_to_display = self.get_numbers_to_display(x_values, excluding)
+        numbers = self.get_number_mobjects(numbers_to_display, **kwargs)
         self.add(numbers)
         self.numbers = numbers
         return self