diff --git a/compiler+runtime/include/cpp/jank/runtime/core/math.hpp b/compiler+runtime/include/cpp/jank/runtime/core/math.hpp
index aac16a5e3..a88c1a127 100644
--- a/compiler+runtime/include/cpp/jank/runtime/core/math.hpp
+++ b/compiler+runtime/include/cpp/jank/runtime/core/math.hpp
@@ -41,6 +41,8 @@ namespace jank::runtime
   object_ref add(obj::ratio_ref l, obj::integer_ref r);
   obj::ratio_ref add(obj::integer_ref l, obj::ratio_ref r);
 
+  object_ref promoting_add(object_ref const l, object_ref const r);
+
   object_ref sub(object_ref l, object_ref r);
   object_ref sub(obj::integer_ref l, object_ref r);
   object_ref sub(object_ref l, obj::integer_ref r);
@@ -64,6 +66,8 @@ namespace jank::runtime
   object_ref sub(i64 l, object_ref r);
   i64 sub(i64 l, i64 r);
 
+  object_ref promoting_sub(object_ref const l, object_ref const r);
+
   object_ref div(object_ref l, object_ref r);
   object_ref div(obj::integer_ref l, object_ref r);
   object_ref div(object_ref l, obj::integer_ref r);
@@ -110,6 +114,8 @@ namespace jank::runtime
   object_ref mul(i64 l, object_ref r);
   i64 mul(i64 l, i64 r);
 
+  object_ref promoting_mul(object_ref const l, object_ref const r);
+
   bool lt(object_ref l, object_ref r);
   bool lt(obj::integer_ref l, object_ref r);
   bool lt(object_ref l, obj::integer_ref r);
@@ -232,7 +238,9 @@ namespace jank::runtime
   object_ref rem(object_ref l, object_ref r);
   object_ref quot(object_ref l, object_ref r);
   object_ref inc(object_ref l);
+  object_ref promoting_inc(object_ref const l);
   object_ref dec(object_ref l);
+  object_ref promoting_dec(object_ref const l);
 
   bool is_zero(object_ref l);
   bool is_pos(object_ref l);
@@ -269,6 +277,8 @@ namespace jank::runtime
   f64 to_real(object_ref o);
 
   bool is_number(object_ref o);
+  object_ref number(object_ref const o);
+
   bool is_integer(object_ref o);
   bool is_real(object_ref o);
   bool is_ratio(object_ref o);
@@ -279,6 +289,7 @@ namespace jank::runtime
   i64 parse_long(object_ref o);
   f64 parse_double(object_ref o);
 
+  bool is_big_integer(object_ref const o);
   obj::big_integer_ref to_big_integer(object_ref const o);
 
   bool is_big_decimal(object_ref const o);
diff --git a/compiler+runtime/src/cpp/jank/runtime/core/math.cpp b/compiler+runtime/src/cpp/jank/runtime/core/math.cpp
index 01382dab5..e6766720f 100644
--- a/compiler+runtime/src/cpp/jank/runtime/core/math.cpp
+++ b/compiler+runtime/src/cpp/jank/runtime/core/math.cpp
@@ -171,6 +171,40 @@ namespace jank::runtime
     return l + r;
   }
 
+  object_ref promoting_add(object_ref const l, object_ref const r)
+  {
+    return visit_number_like(
+      [](auto const typed_l, auto const r) -> object_ref {
+        using LT = typename decltype(typed_l)::value_type;
+
+        return visit_number_like(
+          [](auto const typed_r, auto const &l_val) -> object_ref {
+            using RT = typename decltype(typed_r)::value_type;
+
+            if constexpr(std::same_as<LT, obj::integer> && std::same_as<RT, obj::integer>)
+            {
+              i64 res{};
+
+              if(static_cast<bool>(__builtin_add_overflow(l_val, typed_r->data, &res)))
+              {
+                native_big_integer const l{ l_val };
+                return make_box<obj::big_integer>(l + typed_r->data);
+              }
+
+              return make_box<obj::integer>(res);
+            }
+            else
+            {
+              return make_box(l_val + typed_r->data);
+            }
+          },
+          r,
+          typed_l->data);
+      },
+      l,
+      r);
+  }
+
   object_ref sub(object_ref const l, object_ref const r)
   {
     return visit_number_like(
@@ -306,6 +340,40 @@ namespace jank::runtime
     return l - r;
   }
 
+  object_ref promoting_sub(object_ref const l, object_ref const r)
+  {
+    return visit_number_like(
+      [](auto const typed_l, auto const r) -> object_ref {
+        using LT = typename decltype(typed_l)::value_type;
+
+        return visit_number_like(
+          [](auto const typed_r, auto const &l_val) -> object_ref {
+            using RT = typename decltype(typed_r)::value_type;
+
+            if constexpr(std::same_as<LT, obj::integer> && std::same_as<RT, obj::integer>)
+            {
+              i64 res{};
+
+              if(__builtin_sub_overflow(l_val, typed_r->data, &res))
+              {
+                native_big_integer const l{ l_val };
+                return make_box<obj::big_integer>(l_val - typed_r->data);
+              }
+
+              return make_box<obj::integer>(res);
+            }
+            else
+            {
+              return make_box(l_val - typed_r->data);
+            }
+          },
+          r,
+          typed_l->data);
+      },
+      l,
+      r);
+  }
+
   object_ref div(object_ref const l, object_ref const r)
   {
     return visit_number_like(
@@ -576,6 +644,40 @@ namespace jank::runtime
     return l * r;
   }
 
+  object_ref promoting_mul(object_ref const l, object_ref const r)
+  {
+    return visit_number_like(
+      [](auto const typed_l, auto const r) -> object_ref {
+        using LT = typename decltype(typed_l)::value_type;
+
+        return visit_number_like(
+          [](auto const typed_r, auto const &l_val) -> object_ref {
+            using RT = typename decltype(typed_r)::value_type;
+
+            if constexpr(std::same_as<LT, obj::integer> && std::same_as<RT, obj::integer>)
+            {
+              i64 res{};
+
+              if(__builtin_mul_overflow(l_val, typed_r->data, &res))
+              {
+                native_big_integer const l{ l_val };
+                return make_box<obj::big_integer>(l * typed_r->data);
+              }
+
+              return make_box<obj::integer>(res);
+            }
+            else
+            {
+              return make_box(l_val * typed_r->data);
+            }
+          },
+          r,
+          typed_l->data);
+      },
+      l,
+      r);
+  }
+
   object_ref rem(object_ref const l, object_ref const r)
   {
     return visit_number_like(
@@ -659,6 +761,32 @@ namespace jank::runtime
       l);
   }
 
+  object_ref promoting_inc(object_ref const l)
+  {
+    return visit_number_like(
+      [](auto const typed_l) -> object_ref {
+        using T = typename decltype(typed_l)::value_type;
+
+        if constexpr(std::same_as<T, obj::integer>)
+        {
+          i64 res{};
+
+          if(__builtin_add_overflow(typed_l->data, 1ll, &res))
+          {
+            native_big_integer const v{ typed_l->data };
+            return make_box<obj::big_integer>(v + 1ll);
+          }
+
+          return make_box<obj::integer>(res);
+        }
+        else
+        {
+          return make_box(typed_l->data + 1ll);
+        }
+      },
+      l);
+  }
+
   object_ref dec(object_ref const l)
   {
     return visit_number_like(
@@ -666,6 +794,32 @@ namespace jank::runtime
       l);
   }
 
+  object_ref promoting_dec(object_ref const l)
+  {
+    return visit_number_like(
+      [](auto const typed_l) -> object_ref {
+        using T = typename decltype(typed_l)::value_type;
+
+        if constexpr(std::same_as<T, obj::integer>)
+        {
+          i64 res{};
+
+          if(__builtin_sub_overflow(typed_l->data, 1ll, &res))
+          {
+            native_big_integer const v{ typed_l->data };
+            return make_box<obj::big_integer>(v - 1ll);
+          }
+
+          return make_box<obj::integer>(res);
+        }
+        else
+        {
+          return make_box(typed_l->data - 1ll);
+        }
+      },
+      l);
+  }
+
   bool is_zero(object_ref const l)
   {
     return visit_number_like(
@@ -1710,6 +1864,11 @@ namespace jank::runtime
                              o);
   }
 
+  object_ref number(object_ref const o)
+  {
+    return visit_number_like([](auto const typed_l) -> object_ref { return typed_l; }, o);
+  }
+
   bool is_integer(object_ref const o)
   {
     return o->type == object_type::integer;
@@ -1793,6 +1952,11 @@ namespace jank::runtime
     }
   }
 
+  bool is_big_integer(object_ref const o)
+  {
+    return o->type == object_type::big_integer;
+  }
+
   obj::big_integer_ref to_big_integer(object_ref const o)
   {
     return visit_number_like(
diff --git a/compiler+runtime/src/jank/clojure/core.jank b/compiler+runtime/src/jank/clojure/core.jank
index 9c2cd137a..fdc4c6d3d 100644
--- a/compiler+runtime/src/jank/clojure/core.jank
+++ b/compiler+runtime/src/jank/clojure/core.jank
@@ -1126,7 +1126,7 @@
   ([]
    0)
   ([x]
-   x)
+   (cpp/jank.runtime.number x))
   ([l r]
    (cpp/jank.runtime.add l r))
   ([l r & args]
@@ -1156,7 +1156,7 @@
   ([]
    1)
   ([x]
-   x)
+   (cpp/jank.runtime.number x))
   ([l r]
    (cpp/jank.runtime.mul l r))
   ([l r & args]
@@ -4482,8 +4482,7 @@
   "Returns a number one greater than num. Supports arbitrary precision.
   See also: inc"
   [x]
-  ;; (. clojure.lang.Numbers (incP x))
-  (throw "TODO: port inc'"))
+  (cpp/jank.runtime.promoting_inc x))
 
 ;; ;;math stuff
 ;; (defn ^:private nary-inline
@@ -4509,11 +4508,9 @@
   See also: +"
   ([] 0)
   ([x]
-  ;;  (cast Number x)
-   (throw "TODO: port +'"))
+   (cpp/jank.runtime.number x))
   ([x y]
-  ;;  (. clojure.lang.Numbers (addP x y))
-   (throw "TODO: port +'"))
+   (cpp/jank.runtime.promoting_add x y))
   ([x y & more]
    (reduce +' (+' x y) more)))
 
@@ -4522,11 +4519,9 @@
   See also: *"
   ([] 1)
   ([x]
-  ;;  (cast Number x)
-   (throw "TODO: port *'"))
+   (cpp/jank.runtime.number x))
   ([x y]
-  ;;  (. clojure.lang.Numbers (multiplyP x y))
-  (throw "TODO: port *'"))
+   (cpp/jank.runtime.promoting_mul x y))
   ([x y & more]
    (reduce *' (*' x y) more)))
 
@@ -4535,11 +4530,9 @@
   the ys from x and returns the result. Supports arbitrary precision.
   See also: -"
   ([x]
-  ;;  (. clojure.lang.Numbers (minusP x))
-   (throw "TODO: port -'"))
+   (-' 0 x))
   ([x y]
-  ;;  (. clojure.lang.Numbers (minusP x y))
-   (throw "TODO: port -'"))
+   (cpp/jank.runtime.promoting_sub x y))
   ([x y & more]
    (reduce -' (-' x y) more)))
 
@@ -4556,8 +4549,7 @@
   "Returns a number one less than num. Supports arbitrary precision.
   See also: dec"
   [x]
-  ;; (. clojure.lang.Numbers (decP x))
-  (throw "TODO: port dec'"))
+  (cpp/jank.runtime.promoting_dec x))
 
 (defn unchecked-inc-int
   "Returns a number one greater than x, an int.
@@ -5340,8 +5332,7 @@
 (defn num
   "Coerce to Number"
   [x]
-  ;; (. clojure.lang.Numbers (num x))
-  (throw "TODO: port num"))
+  (cpp/jank.runtime.number x))
 
 (defn long
   "Coerce to long"
diff --git a/compiler+runtime/test/bash/clojure-test-suite/src/jank_test/run_clojure_test_suite.cljc b/compiler+runtime/test/bash/clojure-test-suite/src/jank_test/run_clojure_test_suite.cljc
index e5826c90f..a88e33bba 100644
--- a/compiler+runtime/test/bash/clojure-test-suite/src/jank_test/run_clojure_test_suite.cljc
+++ b/compiler+runtime/test/bash/clojure-test-suite/src/jank_test/run_clojure_test_suite.cljc
@@ -75,7 +75,7 @@
     ;clojure.core-test.nth ; Uncaught exception: index out of bounds: -1, In clojure.core-test.nth$fn_2-64, duplicate definition of symbol '_fn_2_0', https://github.com/jank-lang/jank/issues/244, Exception: index out of bounds: -1
     ;clojure.core-test.nthnext ; Uncaught exception: not a number: nil, In clojure.core-test.nthnext$fn_2-83, duplicate definition of symbol '_fn_2_0', https://github.com/jank-lang/jank/issues/243 , https://github.com/jank-lang/jank/issues/244
     ;clojure.core-test.nthrest ; Uncaught exception: not a number: nil, In clojure.core-test.nthrest$fn_2-85, duplicate definition of symbol '_fn_2_0', https://github.com/jank-lang/jank/issues/243 , https://github.com/jank-lang/jank/issues/244 , https://github.com/jank-lang/jank/issues/247
-    clojure.core-test.num ; Expecting whitespace after the last token. due to M.
+    clojure.core-test.num
     clojure.core-test.number-qmark ; Expecting whitespace after the last token. due to M.
     clojure.core-test.number-range
     ;clojure.core-test.numerator ; Failed a test. Expecting whitespace after the last token. due to M.
@@ -83,7 +83,7 @@
     ;clojure.core-test.or ; unloadable, In clojure.core-test.or$fn_2-159, duplicate definition of symbol '_fn_2_0', unloadable
     ;clojure.core-test.partial ;unloadable
     ;clojure.core-test.plus ; error: Unable to resolve symbol 'Exception'
-    ;clojure.core-test.plus-squote ; error: Unable to resolve symbol 'clojure.lang.BigInt'.
+    ; clojure.core-test.plus-squote
     clojure.core-test.pos-int-qmark ; Expecting whitespace after the last token. due to M.
     ;clojure.core-test.pos-qmark ; Uncaught exception: not a number: nil. Expecting whitespace after the last token. due to M.
     ;clojure.core-test.pr-str ; Uncaught exception: invalid call to clojure.core/pr-str with 2 args provided, In clojure.core-test.pr-str$fn_2-49, duplicate definition of symbol '_fn_2_0', unloadable
@@ -96,7 +96,7 @@
     ;clojure.core-test.quot ; Failed tests. Expecting whitespace after the last token. due to M.
     ;clojure.core-test.rand ; unloadable, In clojure.core-test.rand$fn_2-71, duplicate definition of symbol '_jank_global_init_70', unloadable
     ;clojure.core-test.rand-int ; unloadable, In clojure.core-test.rand-int$fn_2-56, duplicate definition of symbol '_fn_2_0', unloadable
-    clojure.core-test.ratio-qmark ; Expecting whitespace after the last token. due to M.
+    clojure.core-test.ratio-qmark
     ;clojure.core-test.rational-qmark ; (= true (rational? 0N))
     ;clojure.core-test.rationalize ; TODO: port rationalize, Expecting whitespace after the last token. due to M.
     ;clojure.core-test.rem ; Fails the test cases.
@@ -112,7 +112,7 @@
     ;clojure.core-test.slash ; Unable to resolve symbol 'Exception'., Expecting whitespace after the last token. due to M.
     ;clojure.core-test.some-qmark ;Read error (437 - 437): unsupported reader macro
     ;clojure.core-test.star ; error: Unable to resolve symbol 'Exception'.
-    ;clojure.core-test.star-squote ; error: Unable to resolve symbol 'clojure.lang.BigInt'.
+    ; clojure.core-test.star-squote
     ;clojure.core-test.str ; TODO: port double, Expecting whitespace after the last token. due to M.
     clojure.core-test.string-qmark
     ;clojure.core-test.subs ; Uncaught exception: end index 1 is less than start 2, In clojure.core-test.subs$fn_2-70, duplicate definition of symbol '_fn_2_0', https://github.com/jank-lang/jank/issues/244