diff --git a/nac3core/src/toplevel/builtins.rs b/nac3core/src/toplevel/builtins.rs
index 319ae20..a36939a 100644
--- a/nac3core/src/toplevel/builtins.rs
+++ b/nac3core/src/toplevel/builtins.rs
@@ -814,6 +814,66 @@ pub fn get_builtins(primitives: &mut (PrimitiveStore, Unifier)) -> BuiltinInfo {
             )))),
             loc: None,
         })),
+        create_fn_by_codegen(
+            primitives,
+            &var_map,
+            "round",
+            int32,
+            &[(float, "n")],
+            Box::new(|ctx, _, _, args, generator| {
+                let llvm_f64 = ctx.ctx.f64_type();
+                let llvm_i32 = ctx.ctx.i32_type();
+
+                let arg = args[0].1.clone()
+                    .to_basic_value_enum(ctx, generator, ctx.primitives.float)?;
+
+                let intrinsic_fn = ctx.module.get_function("llvm.round.f64").unwrap_or_else(|| {
+                        let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
+
+                        ctx.module.add_function("llvm.round.f64", fn_type, None)
+                    });
+
+                let val = ctx
+                    .builder
+                    .build_call(intrinsic_fn, &[arg.into()], "")
+                    .try_as_basic_value()
+                    .left()
+                    .unwrap();
+                let val_toint = ctx.builder
+                    .build_float_to_signed_int(val.into_float_value(), llvm_i32, "round");
+                Ok(Some(val_toint.into()))
+            }),
+        ),
+        create_fn_by_codegen(
+            primitives,
+            &var_map,
+            "round64",
+            int64,
+            &[(float, "n")],
+            Box::new(|ctx, _, _, args, generator| {
+                let llvm_f64 = ctx.ctx.f64_type();
+                let llvm_i64 = ctx.ctx.i64_type();
+
+                let arg = args[0].1.clone()
+                    .to_basic_value_enum(ctx, generator, ctx.primitives.float)?;
+
+                let intrinsic_fn = ctx.module.get_function("llvm.round.f64").unwrap_or_else(|| {
+                    let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
+
+                    ctx.module.add_function("llvm.round.f64", fn_type, None)
+                });
+
+                let val = ctx
+                    .builder
+                    .build_call(intrinsic_fn, &[arg.into()], "")
+                    .try_as_basic_value()
+                    .left()
+                    .unwrap();
+                let val_toint = ctx.builder
+                    .build_float_to_signed_int(val.into_float_value(), llvm_i64, "round");
+                Ok(Some(val_toint.into()))
+            }),
+        ),
         Arc::new(RwLock::new(TopLevelDef::Function {
             name: "range".into(),
             simple_name: "range".into(),
@@ -996,21 +1056,125 @@ pub fn get_builtins(primitives: &mut (PrimitiveStore, Unifier)) -> BuiltinInfo {
             )))),
             loc: None,
         })),
-        create_fn_by_intrinsic(
+        create_fn_by_codegen(
             primitives,
             &var_map,
             "floor",
-            float,
-            &[(float, "x")],
-            "llvm.floor.f64",
+            int32,
+            &[(float, "n")],
+            Box::new(|ctx, _, _, args, generator| {
+                let llvm_f64 = ctx.ctx.f64_type();
+                let llvm_i32 = ctx.ctx.i32_type();
+
+                let arg = args[0].1.clone()
+                    .to_basic_value_enum(ctx, generator, ctx.primitives.float)?;
+
+                let intrinsic_fn = ctx.module.get_function("llvm.floor.f64").unwrap_or_else(|| {
+                    let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
+
+                    ctx.module.add_function("llvm.floor.f64", fn_type, None)
+                });
+
+                let val = ctx
+                    .builder
+                    .build_call(intrinsic_fn, &[arg.into()], "")
+                    .try_as_basic_value()
+                    .left()
+                    .unwrap();
+                let val_toint = ctx.builder
+                    .build_float_to_signed_int(val.into_float_value(), llvm_i32, "floor");
+                Ok(Some(val_toint.into()))
+            }),
         ),
-        create_fn_by_intrinsic(
+        create_fn_by_codegen(
+            primitives,
+            &var_map,
+            "floor64",
+            int64,
+            &[(float, "n")],
+            Box::new(|ctx, _, _, args, generator| {
+                let llvm_f64 = ctx.ctx.f64_type();
+                let llvm_i64 = ctx.ctx.i64_type();
+
+                let arg = args[0].1.clone()
+                    .to_basic_value_enum(ctx, generator, ctx.primitives.float)?;
+
+                let intrinsic_fn = ctx.module.get_function("llvm.floor.f64").unwrap_or_else(|| {
+                    let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
+
+                    ctx.module.add_function("llvm.floor.f64", fn_type, None)
+                });
+
+                let val = ctx
+                    .builder
+                    .build_call(intrinsic_fn, &[arg.into()], "")
+                    .try_as_basic_value()
+                    .left()
+                    .unwrap();
+                let val_toint = ctx.builder
+                    .build_float_to_signed_int(val.into_float_value(), llvm_i64, "floor");
+                Ok(Some(val_toint.into()))
+            }),
+        ),
+        create_fn_by_codegen(
             primitives,
             &var_map,
             "ceil",
-            float,
-            &[(float, "x")],
-            "llvm.ceil.f64",
+            int32,
+            &[(float, "n")],
+            Box::new(|ctx, _, _, args, generator| {
+                let llvm_f64 = ctx.ctx.f64_type();
+                let llvm_i32 = ctx.ctx.i32_type();
+
+                let arg = args[0].1.clone()
+                    .to_basic_value_enum(ctx, generator, ctx.primitives.float)?;
+
+                let intrinsic_fn = ctx.module.get_function("llvm.ceil.f64").unwrap_or_else(|| {
+                    let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
+
+                    ctx.module.add_function("llvm.ceil.f64", fn_type, None)
+                });
+
+                let val = ctx
+                    .builder
+                    .build_call(intrinsic_fn, &[arg.into()], "")
+                    .try_as_basic_value()
+                    .left()
+                    .unwrap();
+                let val_toint = ctx.builder
+                    .build_float_to_signed_int(val.into_float_value(), llvm_i32, "ceil");
+                Ok(Some(val_toint.into()))
+            }),
+        ),
+        create_fn_by_codegen(
+            primitives,
+            &var_map,
+            "ceil64",
+            int64,
+            &[(float, "n")],
+            Box::new(|ctx, _, _, args, generator| {
+                let llvm_f64 = ctx.ctx.f64_type();
+                let llvm_i64 = ctx.ctx.i64_type();
+
+                let arg = args[0].1.clone()
+                    .to_basic_value_enum(ctx, generator, ctx.primitives.float)?;
+
+                let intrinsic_fn = ctx.module.get_function("llvm.ceil.f64").unwrap_or_else(|| {
+                    let fn_type = llvm_f64.fn_type(&[llvm_f64.into()], false);
+
+                    ctx.module.add_function("llvm.ceil.f64", fn_type, None)
+                });
+
+                let val = ctx
+                    .builder
+                    .build_call(intrinsic_fn, &[arg.into()], "")
+                    .try_as_basic_value()
+                    .left()
+                    .unwrap();
+                let val_toint = ctx.builder
+                    .build_float_to_signed_int(val.into_float_value(), llvm_i64, "ceil");
+                Ok(Some(val_toint.into()))
+            }),
         ),
         Arc::new(RwLock::new({
             let list_var = primitives.1.get_fresh_var(Some("L".into()), None);
@@ -1815,11 +1979,15 @@ pub fn get_builtins(primitives: &mut (PrimitiveStore, Unifier)) -> BuiltinInfo {
             "uint32",
             "uint64",
             "float",
+            "round",
+            "round64",
             "range",
             "str",
             "bool",
             "floor",
+            "floor64",
             "ceil",
+            "ceil64",
             "len",
             "min",
             "max",
diff --git a/nac3standalone/demo/interpret_demo.py b/nac3standalone/demo/interpret_demo.py
index 0339206..e6ccba1 100755
--- a/nac3standalone/demo/interpret_demo.py
+++ b/nac3standalone/demo/interpret_demo.py
@@ -3,6 +3,7 @@
 import sys
 import importlib.util
 import importlib.machinery
+import math
 import numpy as np
 import pathlib
 import scipy
@@ -43,6 +44,12 @@ def Some(v: T) -> Option[T]:
 
 none = Option(None)
 
+def round_away_zero(x):
+    if x >= 0.0:
+        return math.floor(x + 0.5)
+    else:
+        return math.ceil(x - 0.5)
+
 def patch(module):
     def dbl_nan():
         return np.nan
@@ -98,6 +105,14 @@ def patch(module):
     module.Some = Some
     module.none = none
 
+    # Builtin Math functions
+    module.round = round_away_zero
+    module.round64 = round_away_zero
+    module.floor = math.floor
+    module.floor64 = math.floor
+    module.ceil = math.ceil
+    module.ceil64 = math.ceil
+
     # NumPy Math functions
     module.isnan = np.isnan
     module.isinf = np.isinf
@@ -109,8 +124,6 @@ def patch(module):
     module.log10 = np.log10
     module.log2 = np.log2
     module.fabs = np.fabs
-    module.floor = np.floor
-    module.ceil = np.ceil
     module.trunc = np.trunc
     module.sqrt = np.sqrt
     module.rint = np.rint
diff --git a/nac3standalone/demo/src/math.py b/nac3standalone/demo/src/math.py
index 9fa3951..dfbd4ca 100644
--- a/nac3standalone/demo/src/math.py
+++ b/nac3standalone/demo/src/math.py
@@ -2,6 +2,14 @@
 def output_bool(x: bool):
     ...
 
+@extern
+def output_int32(x: int32):
+    ...
+
+@extern
+def output_int64(x: int64):
+    ...
+
 @extern
 def output_float64(x: float):
     ...
@@ -20,6 +28,14 @@ def dbl_pi() -> float:
 def dbl_e() -> float:
     return 2.71828182845904523536028747135266249775724709369995
 
+def test_round():
+    for x in [-1.5, -0.5, 0.5, 1.5]:
+        output_int32(round(x))
+
+def test_round64():
+    for x in [-1.5, -0.5, 0.5, 1.5]:
+        output_int64(round64(x))
+
 def test_isnan():
     for x in [dbl_nan(), 0.0, dbl_inf()]:
         output_bool(isnan(x))
@@ -64,12 +80,20 @@ def test_fabs():
         output_float64(fabs(x))
 
 def test_floor():
-    for x in [-1.5, -0.5, 0.5, 1.5, dbl_inf(), -dbl_inf(), dbl_nan()]:
-        output_float64(floor(x))
+    for x in [-1.5, -0.5, 0.5, 1.5]:
+        output_int32(floor(x))
+
+def test_floor64():
+    for x in [-1.5, -0.5, 0.5, 1.5]:
+        output_int64(floor64(x))
 
 def test_ceil():
-    for x in [-1.5, -0.5, 0.5, 1.5, dbl_inf(), -dbl_inf(), dbl_nan()]:
-        output_float64(ceil(x))
+    for x in [-1.5, -0.5, 0.5, 1.5]:
+        output_int32(ceil(x))
+
+def test_ceil64():
+    for x in [-1.5, -0.5, 0.5, 1.5]:
+        output_int64(ceil64(x))
 
 def test_trunc():
     for x in [-1.5, -0.5, 0.5, 1.5, dbl_inf(), -dbl_inf(), dbl_nan()]:
@@ -192,6 +216,8 @@ def test_nextafter():
             output_float64(nextafter(x1, x2))
 
 def run() -> int32:
+    test_round()
+    test_round64()
     test_isnan()
     test_isinf()
     test_sin()
@@ -203,7 +229,9 @@ def run() -> int32:
     test_log2()
     test_fabs()
     test_floor()
+    test_floor64()
     test_ceil()
+    test_ceil64()
     test_trunc()
     test_sqrt()
     test_rint()