diff --git a/mathics/builtin/atomic/numbers.py b/mathics/builtin/atomic/numbers.py
index 4f8d143a1..6d31f447c 100644
--- a/mathics/builtin/atomic/numbers.py
+++ b/mathics/builtin/atomic/numbers.py
@@ -45,7 +45,7 @@
     SymbolRound,
 )
 from mathics.eval.nevaluator import eval_N
-from mathics.eval.numbers import eval_Accuracy, eval_Precision
+from mathics.eval.numbers.numbers import eval_Accuracy, eval_Precision
 
 SymbolIntegerDigits = Symbol("IntegerDigits")
 SymbolIntegerExponent = Symbol("IntegerExponent")
diff --git a/mathics/builtin/numbers/algebra.py b/mathics/builtin/numbers/algebra.py
index 3ea0052d9..9c21f7782 100644
--- a/mathics/builtin/numbers/algebra.py
+++ b/mathics/builtin/numbers/algebra.py
@@ -17,7 +17,6 @@
 
 import sympy
 
-from mathics.algorithm.simplify import default_complexity_function
 from mathics.builtin.inference import evaluate_predicate
 from mathics.builtin.options import options_to_rules
 from mathics.builtin.scoping import dynamic_scoping
@@ -64,7 +63,8 @@
     SymbolTable,
     SymbolTanh,
 )
-from mathics.eval.numbers import cancel, sympy_factor
+from mathics.eval.numbers.algebra.simplify import default_complexity_function
+from mathics.eval.numbers.numbers import cancel, sympy_factor
 from mathics.eval.parts import walk_parts
 from mathics.eval.patterns import match
 
diff --git a/mathics/builtin/numbers/calculus.py b/mathics/builtin/numbers/calculus.py
index 987d201a0..ad5c38a1d 100644
--- a/mathics/builtin/numbers/calculus.py
+++ b/mathics/builtin/numbers/calculus.py
@@ -15,18 +15,6 @@
 import numpy as np
 import sympy
 
-from mathics.algorithm.integrators import (
-    _fubini,
-    _internal_adaptative_simpsons_rule,
-    decompose_domain,
-    eval_D_to_Integral,
-)
-from mathics.algorithm.series import (
-    build_series,
-    series_derivative,
-    series_plus_series,
-    series_times_series,
-)
 from mathics.builtin.scoping import dynamic_scoping
 from mathics.core.atoms import (
     Atom,
@@ -90,6 +78,18 @@
 )
 from mathics.eval.makeboxes import format_element
 from mathics.eval.nevaluator import eval_N
+from mathics.eval.numbers.calculus.integrators import (
+    _fubini,
+    _internal_adaptative_simpsons_rule,
+    decompose_domain,
+    eval_D_to_Integral,
+)
+from mathics.eval.numbers.calculus.series import (
+    build_series,
+    series_derivative,
+    series_plus_series,
+    series_times_series,
+)
 
 # These should be used in lower-level formatting
 SymbolDifferentialD = Symbol("System`DifferentialD")
@@ -748,7 +748,9 @@ class FindMaximum(_BaseFinder):
     messages = _BaseFinder.messages.copy()
     summary_text = "local maximum optimization"
     try:
-        from mathics.algorithm.optimizers import native_local_optimizer_methods
+        from mathics.eval.numbers.calculus.optimizers import (
+            native_local_optimizer_methods,
+        )
 
         methods.update(native_local_optimizer_methods)
     except Exception:
@@ -797,7 +799,7 @@ class FindMinimum(_BaseFinder):
     messages = _BaseFinder.messages.copy()
     summary_text = "local minimum optimization"
     try:
-        from mathics.algorithm.optimizers import (
+        from mathics.eval.numbers.calculus.optimizers import (
             native_local_optimizer_methods,
             native_optimizer_messages,
         )
@@ -883,7 +885,7 @@ class FindRoot(_BaseFinder):
     )
 
     try:
-        from mathics.algorithm.optimizers import (
+        from mathics.eval.numbers.calculus.optimizers import (
             native_findroot_messages,
             native_findroot_methods,
         )
@@ -1349,7 +1351,7 @@ class NIntegrate(Builtin):
 
     try:
         # builtin integrators
-        from mathics.algorithm.integrators import (
+        from mathics.eval.numbers.calculus.integrators import (
             integrator_messages,
             integrator_methods,
         )
diff --git a/mathics/core/builtin.py b/mathics/core/builtin.py
index 31845afa7..3e26f3a71 100644
--- a/mathics/core/builtin.py
+++ b/mathics/core/builtin.py
@@ -63,7 +63,7 @@
     SymbolSequence,
 )
 from mathics.eval.arithmetic import eval_mpmath_function
-from mathics.eval.numbers import cancel
+from mathics.eval.numbers.numbers import cancel
 from mathics.eval.numerify import numerify
 from mathics.eval.scoping import dynamic_scoping
 
diff --git a/mathics/eval/numbers/__init__.py b/mathics/eval/numbers/__init__.py
new file mode 100644
index 000000000..6166b84b7
--- /dev/null
+++ b/mathics/eval/numbers/__init__.py
@@ -0,0 +1,4 @@
+# -*- coding: utf-8 -*-
+"""
+Implementation of mathics.builtin.numbers
+"""
diff --git a/mathics/eval/numbers/algebra/__init__.py b/mathics/eval/numbers/algebra/__init__.py
new file mode 100644
index 000000000..20769ed33
--- /dev/null
+++ b/mathics/eval/numbers/algebra/__init__.py
@@ -0,0 +1,4 @@
+# -*- coding: utf-8 -*-
+"""
+Implementation of  mathics.builtin.numbers.algebra
+"""
diff --git a/mathics/algorithm/simplify.py b/mathics/eval/numbers/algebra/simplify.py
similarity index 100%
rename from mathics/algorithm/simplify.py
rename to mathics/eval/numbers/algebra/simplify.py
diff --git a/mathics/eval/numbers/calculus/__init__.py b/mathics/eval/numbers/calculus/__init__.py
new file mode 100644
index 000000000..5f2e067a0
--- /dev/null
+++ b/mathics/eval/numbers/calculus/__init__.py
@@ -0,0 +1,4 @@
+# -*- coding: utf-8 -*-
+"""
+Implementation of mathics.builtin.numbers.calculus
+"""
diff --git a/mathics/algorithm/integrators.py b/mathics/eval/numbers/calculus/integrators.py
similarity index 99%
rename from mathics/algorithm/integrators.py
rename to mathics/eval/numbers/calculus/integrators.py
index e10ef8999..31e9d4884 100644
--- a/mathics/algorithm/integrators.py
+++ b/mathics/eval/numbers/calculus/integrators.py
@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
-
+"""
+Implementation of builtin function integrators.
+"""
 import numpy as np
 
 from mathics.core.atoms import Integer, Integer0, Number
diff --git a/mathics/algorithm/optimizers.py b/mathics/eval/numbers/calculus/optimizers.py
similarity index 99%
rename from mathics/algorithm/optimizers.py
rename to mathics/eval/numbers/calculus/optimizers.py
index 6fd40270b..cfdba2b5a 100644
--- a/mathics/algorithm/optimizers.py
+++ b/mathics/eval/numbers/calculus/optimizers.py
@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
-
+"""
+Implementation of builtin optimizers.
+"""
 from typing import Optional
 
 from mathics.builtin.scoping import dynamic_scoping
diff --git a/mathics/algorithm/series.py b/mathics/eval/numbers/calculus/series.py
similarity index 99%
rename from mathics/algorithm/series.py
rename to mathics/eval/numbers/calculus/series.py
index c627fd7ec..2cbb5cb55 100644
--- a/mathics/algorithm/series.py
+++ b/mathics/eval/numbers/calculus/series.py
@@ -1,3 +1,7 @@
+# -*- coding: utf-8 -*-
+"""
+Implementation of Series handling functions.
+"""
 from mathics.core.atoms import Integer, Integer0, Rational
 from mathics.core.convert.expression import to_mathics_list
 from mathics.core.expression import Expression
diff --git a/mathics/eval/numbers.py b/mathics/eval/numbers/numbers.py
similarity index 98%
rename from mathics/eval/numbers.py
rename to mathics/eval/numbers/numbers.py
index 7389ac8d3..628043d4e 100644
--- a/mathics/eval/numbers.py
+++ b/mathics/eval/numbers/numbers.py
@@ -1,3 +1,8 @@
+# -*- coding: utf-8 -*-
+"""
+Implementation of numbers handling functions.
+"""
+
 from typing import Optional
 
 import mpmath