diff --git a/tests/interpreter/cases/builtins/comparison.yaml b/tests/interpreter/cases/builtins/comparison/tests.yaml
similarity index 100%
rename from tests/interpreter/cases/builtins/comparison.yaml
rename to tests/interpreter/cases/builtins/comparison/tests.yaml
diff --git a/tests/interpreter/cases/builtins/numbers.yaml b/tests/interpreter/cases/builtins/numbers.yaml
deleted file mode 100644
index b56f5f2..0000000
--- a/tests/interpreter/cases/builtins/numbers.yaml
+++ /dev/null
@@ -1,419 +0,0 @@
-# Copyright (c) Microsoft Corporation.
-# Licensed under the MIT License.
-
-cases:
-  - note: abs
-    data: {}
-    modules:
-      - |
-        package test
-        x = [abs(-9), abs(9), abs(-9.1), abs(9.1)]
-
-        # Undefined
-        y { false }
-        z = abs(y)
-    query: data.test
-    want_result:
-      x: [9, 9, 9.1, 9.1]
-
-  - note: abs-extra-args
-    data: {}
-    modules:
-      - |
-        package test
-        x = abs(-9, 10)
-    query: data.test.x
-    error: "`abs` expects 1 argument"
-
-  - note: abs-invalid-type
-    data: {}
-    modules:
-      - |
-        package test
-        x = abs("-9")
-    query: data.test.x
-    error: "`abs` expects numeric argument"
-
-  - note: ceil
-    data: {}
-    modules:
-      - |
-        package test
-        x = [ceil(9.1), ceil(-9.1), ceil(9), ceil(-9)]
-        # Undefined
-        y { false }
-        z = ceil(y)
-    query: data.test
-    want_result:
-      x: [10, -9, 9, -9]
-
-  - note: ceil-extra-args
-    data: {}
-    modules:
-      - |
-        package test
-        x = ceil(-9, 10)
-    query: data.test.x
-    error: "`ceil` expects 1 argument"
-
-  - note: ceil-invalid-type
-    data: {}
-    modules:
-      - |
-        package test
-        x = ceil("-9")
-    query: data.test.x
-    error: "`ceil` expects numeric argument"
-
-  - note: floor
-    data: {}
-    modules:
-      - |
-        package test
-        x = [floor(9.1), floor(-9.1), floor(9), floor(-9)]
-        # Undefined
-        y { false }
-        z = floor(y)
-    query: data.test
-    want_result:
-      x: [9, -10, 9, -9]
-
-  - note: floor-extra-args
-    data: {}
-    modules:
-      - |
-        package test
-        x = floor(-9, 10)
-    query: data.test.x
-    error: "`floor` expects 1 argument"
-
-  - note: floor-invalid-type
-    data: {}
-    modules:
-      - |
-        package test
-        x = floor("-9")
-    query: data.test.x
-    error: "`floor` expects numeric argument"
-
-  - note: numbers.range
-    data: {}
-    modules:
-      - |
-        package test
-        r1 = numbers.range(1, 5)
-        r2 = numbers.range(5, 1)
-        r3 = numbers.range(-1, -5)
-        r4 = numbers.range(-5, -1)
-
-        # Single item range
-        r5 = numbers.range(8, 8)
-
-        # Non-integer start and end result in Undefined.
-        r6 = numbers.range(1.01, 5)
-        r7 = numbers.range(1, 5.01)
-
-        y { false }
-        r8 = numbers.range(y, 10)
-        r9 = numbers.range(10, y)
-
-    query: data.test
-    want_result:
-      r1: [1, 2, 3, 4, 5]
-      r2: [5, 4, 3, 2, 1]
-      r3: [-1, -2, -3, -4, -5]
-      r4: [-5, -4, -3, -2, -1]
-      r5: [8]
-
-  - note: numbers.range-less-args
-    data: {}
-    modules:
-      - |
-        package test
-        x = numbers.range(1)
-    query: data.test.x
-    error: "`numbers.range` expects 2 arguments"
-
-  - note: numbers.range-more-args
-    data: {}
-    modules:
-      - |
-        package test
-        x = numbers.range(1, 2, 3)
-    query: data.test.x
-    error: "`numbers.range` expects 2 arguments"
-
-  - note: numbers.range-invalid-start
-    data: {}
-    modules:
-      - |
-        package test
-        x = numbers.range("1", 2)
-    query: data.test.x
-    error: "`numbers.range` expects numeric argument"
-
-  - note: numbers.range-invalid-end
-    data: {}
-    modules:
-      - |
-        package test
-        x = numbers.range(1, "2")
-    query: data.test.x
-    error: "`numbers.range` expects numeric argument"
-
-  - note: round
-    data: {}
-    modules:
-      - |
-        package test
-        x = [round(-9.4), round(-9.5), round(-9.6),
-             round(9.4), round(9.5), round(9.6),
-             round(8), round(-8)]
-
-        # Undefined
-        y { false }
-        z = round(y)
-    query: data.test.x
-    want_result: [-9, -10, -10, 9, 10, 10, 8, -8]
-
-  - note: round-extra-args
-    data: {}
-    modules:
-      - |
-        package test
-        x = round(-9, 10)
-    query: data.test.x
-    error: "`round` expects 1 argument"
-
-  - note: round-invalid-type
-    data: {}
-    modules:
-      - |
-        package test
-        x = round("-9")
-    query: data.test.x
-    error: "`round` expects numeric argument"
-
-  - note: rand.intn
-    data: {}
-    modules:
-      - |
-        package test
-        x = rand.intn("x", 50000)
-        y = rand.intn("y", 50000)
-        z = [p |
-           p := rand.intn("x", 50000)
-        ]
-        a = rand.intn("x", 25000)
-
-        results = [
-          x == z[0],
-          x != y,
-          x != a,
-          rand.intn("b", 0)
-        ]
-    query: data.test.results
-    want_result: [true, true, true, 0]
-
-  - note: rand.intn-undefined
-    data: {}
-    modules:
-      - |
-        package test
-        y { false }
-        r1 = rand.intn(y, 10)
-        r2 = rand.intn(10, y)
-        r3 = rand.intn("a", 10.3)
-    query: data.test
-    want_result: {}
-
-  - note: rand.intn-extra-args
-    data: {}
-    modules:
-      - |
-        package test
-        x = rand.intn("abc", 10, 11)
-    query: data.test.x
-    error: "`rand.intn` expects 2 arguments"
-
-  - note: rand.intn-less-args
-    data: {}
-    modules:
-      - |
-        package test
-        x = rand.intn("abc")
-    query: data.test.x
-    error: "`rand.intn` expects 2 arguments"
-
-  - note: rand.intn-invalid-type-1
-    data: {}
-    modules:
-      - |
-        package test
-        x = rand.intn(1, 2)
-    query: data.test.x
-    error: "`rand.intn` expects string argument"
-
-  - note: rand.intn-invalid-type-2
-    data: {}
-    modules:
-      - |
-        package test
-        x = rand.intn("a", "b")
-    query: data.test.x
-    error: "`rand.intn` expects numeric argument"
-
-
-  - note: div
-    data: {}
-    modules:
-      - |
-        package test
-        import future.keywords.if
-
-        x = 1/3
-
-        # Undefined
-        y if false
-        a = 1 / 0
-        b = y / 1
-        c = 1 / y
-        d = 13.3 % 3
-        e = 13 % 3.1
-    query: data.test
-    want_result:
-      x: 0.3333333333333333
-
-  - note: div-non-numeric
-    data: {}
-    modules:
-      - |
-        package test
-        x = "1" / 9
-    query: data.test.x
-    error: "`div` expects numeric argument."
-
-  - note: mod
-    data: {}
-    modules:
-      - |
-        package test
-        x = 10%3
-
-        # Undefined
-        y { false }
-        a = 1 % 0
-        b = y % 1
-        c = 1 % y
-    query: data.test
-    want_result:
-      x : 1
-
-  - note: mod-non-numeric
-    data: {}
-    modules:
-      - |
-        package test
-        x = "1" % 9
-    query: data.test.x
-    error: "`mod` expects numeric argument."
-
-  - note: mod-undefined
-    data: {}
-    modules:
-      - |
-        package test
-        a { false }
-        x = a % 10
-    query: data.test
-    want_result: {}
-
-  - note: mod-by-zero
-    data: {}
-    modules:
-      - |
-        package test
-        x = 1%0
-    query: data.test
-    want_result: {}
-
-  - note: mul
-    data: {}
-    modules:
-      - |
-        package test
-        x = 3 * -1 * 4.5
-        # Undefined
-        y { false }
-        a = 1 * y
-        b = y * 1
-    query: data.test
-    want_result:
-      x: -13.5
-
-  - note: mul-non-numeric
-    data: {}
-    modules:
-      - |
-        package test
-        x = "1" * 9
-    query: data.test.x
-    error: "`mul` expects numeric argument."
-
-  - note: add
-    data: {}
-    modules:
-      - |
-        package test
-        x = 3 + -1 + 4.5
-        # Undefined
-        y { false }
-        a = 1 + y
-        b = y + 1
-    query: data.test
-    want_result:
-      x: 6.5
-
-  - note: add-non-numeric
-    data: {}
-    modules:
-      - |
-        package test
-        x = "1" + 9
-    query: data.test.x
-    error: "`add` expects numeric argument."
-
-  - note: sub
-    data: {}
-    modules:
-      - |
-        package test
-        x = 3 - -1 - 4.5
-        # Undefined
-        y { false }
-        a = 1 - y
-        b = y - 1
-    query: data.test
-    want_result:
-      x: -0.5
-
-  - note: sub-non-numeric
-    data: {}
-    modules:
-      - |
-        package test
-        x = "1" - 9
-    query: data.test.x
-    error: "`sub` expects numeric argument."
-
-  - note: all
-    data: {}
-    modules:
-      - |
-        package test
-        x = 16 / 2 % 5 / 2
-    query: data.test
-    want_result:
-      x: 1.5
-
-  # TODO: Lockdown associativity and precedence of operators.
diff --git a/tests/interpreter/cases/builtins/numbers/abs.yaml b/tests/interpreter/cases/builtins/numbers/abs.yaml
new file mode 100644
index 0000000..5be7c73
--- /dev/null
+++ b/tests/interpreter/cases/builtins/numbers/abs.yaml
@@ -0,0 +1,35 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+cases:
+  - note: abs
+    data: {}
+    modules:
+      - |
+        package test
+        x = [abs(-9), abs(9), abs(-9.1), abs(9.1)]
+
+        # Undefined
+        y { false }
+        z = abs(y)
+    query: data.test
+    want_result:
+      x: [9, 9, 9.1, 9.1]
+
+  - note: extra-args
+    data: {}
+    modules:
+      - |
+        package test
+        x = abs(-9, 10)
+    query: data.test.x
+    error: "`abs` expects 1 argument"
+
+  - note: invalid-type
+    data: {}
+    modules:
+      - |
+        package test
+        x = abs("-9")
+    query: data.test.x
+    error: "`abs` expects numeric argument"
diff --git a/tests/interpreter/cases/builtins/numbers/add.yaml b/tests/interpreter/cases/builtins/numbers/add.yaml
new file mode 100644
index 0000000..7ae3e17
--- /dev/null
+++ b/tests/interpreter/cases/builtins/numbers/add.yaml
@@ -0,0 +1,26 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+cases:
+  - note: add
+    data: {}
+    modules:
+      - |
+        package test
+        x = 3 + -1 + 4.5
+        # Undefined
+        y { false }
+        a = 1 + y
+        b = y + 1
+    query: data.test
+    want_result:
+      x: 6.5
+
+  - note: non-numeric
+    data: {}
+    modules:
+      - |
+        package test
+        x = "1" + 9
+    query: data.test.x
+    error: "`add` expects numeric argument."
diff --git a/tests/interpreter/cases/builtins/numbers/associativity.yaml b/tests/interpreter/cases/builtins/numbers/associativity.yaml
new file mode 100644
index 0000000..add4cc2
--- /dev/null
+++ b/tests/interpreter/cases/builtins/numbers/associativity.yaml
@@ -0,0 +1,5 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+# TODO: Lockdown associativity and precedence of operators.
+cases: []
diff --git a/tests/interpreter/cases/builtins/numbers/ceil.yaml b/tests/interpreter/cases/builtins/numbers/ceil.yaml
new file mode 100644
index 0000000..4c28176
--- /dev/null
+++ b/tests/interpreter/cases/builtins/numbers/ceil.yaml
@@ -0,0 +1,34 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+cases:
+  - note: ceil
+    data: {}
+    modules:
+      - |
+        package test
+        x = [ceil(9.1), ceil(-9.1), ceil(9), ceil(-9)]
+        # Undefined
+        y { false }
+        z = ceil(y)
+    query: data.test
+    want_result:
+      x: [10, -9, 9, -9]
+
+  - note: extra-args
+    data: {}
+    modules:
+      - |
+        package test
+        x = ceil(-9, 10)
+    query: data.test.x
+    error: "`ceil` expects 1 argument"
+
+  - note: invalid-type
+    data: {}
+    modules:
+      - |
+        package test
+        x = ceil("-9")
+    query: data.test.x
+    error: "`ceil` expects numeric argument"
diff --git a/tests/interpreter/cases/builtins/numbers/div.yaml b/tests/interpreter/cases/builtins/numbers/div.yaml
new file mode 100644
index 0000000..1d74ead
--- /dev/null
+++ b/tests/interpreter/cases/builtins/numbers/div.yaml
@@ -0,0 +1,32 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+cases:
+  - note: div
+    data: {}
+    modules:
+      - |
+        package test
+        import future.keywords.if
+
+        x = 1/3
+
+        # Undefined
+        y if false
+        a = 1 / 0
+        b = y / 1
+        c = 1 / y
+        d = 13.3 % 3
+        e = 13 % 3.1
+    query: data.test
+    want_result:
+      x: 0.3333333333333333
+
+  - note: non-numeric
+    data: {}
+    modules:
+      - |
+        package test
+        x = "1" / 9
+    query: data.test.x
+    error: "`div` expects numeric argument."
diff --git a/tests/interpreter/cases/builtins/numbers/floor.yaml b/tests/interpreter/cases/builtins/numbers/floor.yaml
new file mode 100644
index 0000000..1691c4a
--- /dev/null
+++ b/tests/interpreter/cases/builtins/numbers/floor.yaml
@@ -0,0 +1,35 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+cases:
+  - note: floor
+    data: {}
+    modules:
+      - |
+        package test
+        x = [floor(9.1), floor(-9.1), floor(9), floor(-9)]
+        # Undefined
+        y { false }
+        z = floor(y)
+    query: data.test
+    want_result:
+      x: [9, -10, 9, -9]
+
+  - note: extra-args
+    data: {}
+    modules:
+      - |
+        package test
+        x = floor(-9, 10)
+    query: data.test.x
+    error: "`floor` expects 1 argument"
+
+  - note: invalid-type
+    data: {}
+    modules:
+      - |
+        package test
+        x = floor("-9")
+    query: data.test.x
+    error: "`floor` expects numeric argument"
+
diff --git a/tests/interpreter/cases/builtins/numbers/intn.yaml b/tests/interpreter/cases/builtins/numbers/intn.yaml
new file mode 100644
index 0000000..4d6ada8
--- /dev/null
+++ b/tests/interpreter/cases/builtins/numbers/intn.yaml
@@ -0,0 +1,72 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+cases:
+  - note: rand.intn
+    data: {}
+    modules:
+      - |
+        package test
+        x = rand.intn("x", 50000)
+        y = rand.intn("y", 50000)
+        z = [p |
+           p := rand.intn("x", 50000)
+        ]
+        a = rand.intn("x", 25000)
+
+        results = [
+          x == z[0],
+          x != y,
+          x != a,
+          rand.intn("b", 0)
+        ]
+    query: data.test.results
+    want_result: [true, true, true, 0]
+
+  - note: undefined
+    data: {}
+    modules:
+      - |
+        package test
+        y { false }
+        r1 = rand.intn(y, 10)
+        r2 = rand.intn(10, y)
+        r3 = rand.intn("a", 10.3)
+    query: data.test
+    want_result: {}
+
+  - note: extra-args
+    data: {}
+    modules:
+      - |
+        package test
+        x = rand.intn("abc", 10, 11)
+    query: data.test.x
+    error: "`rand.intn` expects 2 arguments"
+
+  - note: less-args
+    data: {}
+    modules:
+      - |
+        package test
+        x = rand.intn("abc")
+    query: data.test.x
+    error: "`rand.intn` expects 2 arguments"
+
+  - note: invalid-type-1
+    data: {}
+    modules:
+      - |
+        package test
+        x = rand.intn(1, 2)
+    query: data.test.x
+    error: "`rand.intn` expects string argument"
+
+  - note: invalid-type-2
+    data: {}
+    modules:
+      - |
+        package test
+        x = rand.intn("a", "b")
+    query: data.test.x
+    error: "`rand.intn` expects numeric argument"
diff --git a/tests/interpreter/cases/builtins/numbers/mod.yaml b/tests/interpreter/cases/builtins/numbers/mod.yaml
new file mode 100644
index 0000000..a888296
--- /dev/null
+++ b/tests/interpreter/cases/builtins/numbers/mod.yaml
@@ -0,0 +1,47 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+cases:
+  - note: mod
+    data: {}
+    modules:
+      - |
+        package test
+        x = 10%3
+
+        # Undefined
+        y { false }
+        a = 1 % 0
+        b = y % 1
+        c = 1 % y
+    query: data.test
+    want_result:
+      x : 1
+
+  - note: non-numeric
+    data: {}
+    modules:
+      - |
+        package test
+        x = "1" % 9
+    query: data.test.x
+    error: "`mod` expects numeric argument."
+
+  - note: undefined
+    data: {}
+    modules:
+      - |
+        package test
+        a { false }
+        x = a % 10
+    query: data.test
+    want_result: {}
+
+  - note: by-zero
+    data: {}
+    modules:
+      - |
+        package test
+        x = 1%0
+    query: data.test
+    want_result: {}
diff --git a/tests/interpreter/cases/builtins/numbers/mul.yaml b/tests/interpreter/cases/builtins/numbers/mul.yaml
new file mode 100644
index 0000000..ba7764f
--- /dev/null
+++ b/tests/interpreter/cases/builtins/numbers/mul.yaml
@@ -0,0 +1,26 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+cases:
+  - note: mul
+    data: {}
+    modules:
+      - |
+        package test
+        x = 3 * -1 * 4.5
+        # Undefined
+        y { false }
+        a = 1 * y
+        b = y * 1
+    query: data.test
+    want_result:
+      x: -13.5
+
+  - note: non-numeric
+    data: {}
+    modules:
+      - |
+        package test
+        x = "1" * 9
+    query: data.test.x
+    error: "`mul` expects numeric argument."
diff --git a/tests/interpreter/cases/builtins/numbers/range.yaml b/tests/interpreter/cases/builtins/numbers/range.yaml
new file mode 100644
index 0000000..4f728bf
--- /dev/null
+++ b/tests/interpreter/cases/builtins/numbers/range.yaml
@@ -0,0 +1,68 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+cases:
+  - note: numbers.range
+    data: {}
+    modules:
+      - |
+        package test
+        r1 = numbers.range(1, 5)
+        r2 = numbers.range(5, 1)
+        r3 = numbers.range(-1, -5)
+        r4 = numbers.range(-5, -1)
+
+        # Single item range
+        r5 = numbers.range(8, 8)
+
+        # Non-integer start and end result in Undefined.
+        r6 = numbers.range(1.01, 5)
+        r7 = numbers.range(1, 5.01)
+
+        y { false }
+        r8 = numbers.range(y, 10)
+        r9 = numbers.range(10, y)
+
+    query: data.test
+    want_result:
+      r1: [1, 2, 3, 4, 5]
+      r2: [5, 4, 3, 2, 1]
+      r3: [-1, -2, -3, -4, -5]
+      r4: [-5, -4, -3, -2, -1]
+      r5: [8]
+
+  - note: less-args
+    data: {}
+    modules:
+      - |
+        package test
+        x = numbers.range(1)
+    query: data.test.x
+    error: "`numbers.range` expects 2 arguments"
+
+  - note: more-args
+    data: {}
+    modules:
+      - |
+        package test
+        x = numbers.range(1, 2, 3)
+    query: data.test.x
+    error: "`numbers.range` expects 2 arguments"
+
+  - note: invalid-start
+    data: {}
+    modules:
+      - |
+        package test
+        x = numbers.range("1", 2)
+    query: data.test.x
+    error: "`numbers.range` expects numeric argument"
+
+  - note: invalid-end
+    data: {}
+    modules:
+      - |
+        package test
+        x = numbers.range(1, "2")
+    query: data.test.x
+    error: "`numbers.range` expects numeric argument"
diff --git a/tests/interpreter/cases/builtins/numbers/round.yaml b/tests/interpreter/cases/builtins/numbers/round.yaml
new file mode 100644
index 0000000..986eab8
--- /dev/null
+++ b/tests/interpreter/cases/builtins/numbers/round.yaml
@@ -0,0 +1,36 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+cases:
+  - note: round
+    data: {}
+    modules:
+      - |
+        package test
+        x = [round(-9.4), round(-9.5), round(-9.6),
+             round(9.4), round(9.5), round(9.6),
+             round(8), round(-8)]
+
+        # Undefined
+        y { false }
+        z = round(y)
+    query: data.test.x
+    want_result: [-9, -10, -10, 9, 10, 10, 8, -8]
+
+  - note: extra-args
+    data: {}
+    modules:
+      - |
+        package test
+        x = round(-9, 10)
+    query: data.test.x
+    error: "`round` expects 1 argument"
+
+  - note: invalid-type
+    data: {}
+    modules:
+      - |
+        package test
+        x = round("-9")
+    query: data.test.x
+    error: "`round` expects numeric argument"
diff --git a/tests/interpreter/cases/builtins/numbers/sub.yaml b/tests/interpreter/cases/builtins/numbers/sub.yaml
new file mode 100644
index 0000000..d2eac9a
--- /dev/null
+++ b/tests/interpreter/cases/builtins/numbers/sub.yaml
@@ -0,0 +1,36 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+cases:
+  - note: sub
+    data: {}
+    modules:
+      - |
+        package test
+        x = 3 - -1 - 4.5
+        # Undefined
+        y { false }
+        a = 1 - y
+        b = y - 1
+    query: data.test
+    want_result:
+      x: -0.5
+
+  - note: non-numeric
+    data: {}
+    modules:
+      - |
+        package test
+        x = "1" - 9
+    query: data.test.x
+    error: "`sub` expects numeric argument."
+
+  - note: all
+    data: {}
+    modules:
+      - |
+        package test
+        x = 16 / 2 % 5 / 2
+    query: data.test
+    want_result:
+      x: 1.5
diff --git a/tests/interpreter/cases/builtins/types.yaml b/tests/interpreter/cases/builtins/types/tests.yaml
similarity index 100%
rename from tests/interpreter/cases/builtins/types.yaml
rename to tests/interpreter/cases/builtins/types/tests.yaml