diff --git a/builtins/abs.go b/builtins/abs.go
new file mode 100644
index 0000000..eeb8399
--- /dev/null
+++ b/builtins/abs.go
@@ -0,0 +1,20 @@
+package builtins
+
+import "monkey/object"
+
+// Abs  ...
+func Abs(args ...object.Object) object.Object {
+	if len(args) != 1 {
+		return newError("wrong number of arguments. got=%d, want=1",
+			len(args))
+	}
+
+	if i, ok := args[0].(*object.Integer); ok {
+		value := i.Value
+		if value < 0 {
+			value = value * -1
+		}
+		return &object.Integer{Value: value}
+	}
+	return newError("argument to `abs` not supported, got %s", args[0].Type())
+}
diff --git a/builtins/bin.go b/builtins/bin.go
new file mode 100644
index 0000000..e7ae87e
--- /dev/null
+++ b/builtins/bin.go
@@ -0,0 +1,20 @@
+package builtins
+
+import (
+	"fmt"
+	"monkey/object"
+	"strconv"
+)
+
+// Bin  ...
+func Bin(args ...object.Object) object.Object {
+	if len(args) != 1 {
+		return newError("wrong number of arguments. got=%d, want=1",
+			len(args))
+	}
+
+	if i, ok := args[0].(*object.Integer); ok {
+		return &object.String{Value: fmt.Sprintf("0b%s", strconv.FormatInt(i.Value, 2))}
+	}
+	return newError("argument to `bin` not supported, got %s", args[0].Type())
+}
diff --git a/builtins/builtins.go b/builtins/builtins.go
index 5ecfeda..284bcaf 100644
--- a/builtins/builtins.go
+++ b/builtins/builtins.go
@@ -31,6 +31,16 @@ var Builtins = map[string]*object.Builtin{
 	"read":   {Name: "read", Fn: Read},
 	"write":  {Name: "write", Fn: Write},
 	"ffi":    {Name: "ffi", Fn: FFI},
+	"abs":    {Name: "abs", Fn: Abs},
+	"bin":    {Name: "bin", Fn: Bin},
+	"hex":    {Name: "hex", Fn: Hex},
+	"ord":    {Name: "ord", Fn: Ord},
+	"chr":    {Name: "chr", Fn: Chr},
+	"divmod": {Name: "divmod", Fn: Divmod},
+	"hash":   {Name: "hash", Fn: HashOf},
+	"id":     {Name: "id", Fn: IdOf},
+	"oct":    {Name: "oct", Fn: Oct},
+	"pow":    {Name: "pow", Fn: Pow},
 }
 
 // BuiltinsIndex ...
diff --git a/builtins/chr.go b/builtins/chr.go
new file mode 100644
index 0000000..6619110
--- /dev/null
+++ b/builtins/chr.go
@@ -0,0 +1,19 @@
+package builtins
+
+import (
+	"fmt"
+	"monkey/object"
+)
+
+// Chr ...
+func Chr(args ...object.Object) object.Object {
+	if len(args) != 1 {
+		return newError("wrong number of arguments. got=%d, want=1",
+			len(args))
+	}
+
+	if i, ok := args[0].(*object.Integer); ok {
+		return &object.String{Value: fmt.Sprintf("%c", rune(i.Value))}
+	}
+	return newError("argument to `chr` not supported, got %s", args[0].Type())
+}
diff --git a/builtins/divmod.go b/builtins/divmod.go
new file mode 100644
index 0000000..01701b1
--- /dev/null
+++ b/builtins/divmod.go
@@ -0,0 +1,24 @@
+package builtins
+
+import "monkey/object"
+
+// Divmod ...
+func Divmod(args ...object.Object) object.Object {
+	if len(args) != 2 {
+		return newError("wrong number of arguments. got=%d, want=2",
+			len(args))
+	}
+
+	if a, ok := args[0].(*object.Integer); ok {
+		if b, ok := args[1].(*object.Integer); ok {
+			elements := make([]object.Object, 2)
+			elements[0] = &object.Integer{Value: a.Value / b.Value}
+			elements[1] = &object.Integer{Value: a.Value % b.Value}
+			return &object.Array{Elements: elements}
+		} else {
+			return newError("expected argument #2 to `divmod` to be `int` got=%s", args[1].Type())
+		}
+	} else {
+		return newError("expected argument #1 to `divmod` to be `int` got=%s", args[0].Type())
+	}
+}
diff --git a/builtins/hash.go b/builtins/hash.go
new file mode 100644
index 0000000..c13a170
--- /dev/null
+++ b/builtins/hash.go
@@ -0,0 +1,16 @@
+package builtins
+
+import "monkey/object"
+
+// HashOf ...
+func HashOf(args ...object.Object) object.Object {
+	if len(args) != 1 {
+		return newError("wrong number of arguments. got=%d, want=1",
+			len(args))
+	}
+
+	if hash, ok := args[0].(object.Hashable); ok {
+		return &object.Integer{Value: int64(hash.HashKey().Value)}
+	}
+	return newError("argument #1 to `hash()` is not hashable: %s", args[0].Inspect())
+}
diff --git a/builtins/hex.go b/builtins/hex.go
new file mode 100644
index 0000000..952ce1d
--- /dev/null
+++ b/builtins/hex.go
@@ -0,0 +1,20 @@
+package builtins
+
+import (
+	"fmt"
+	"monkey/object"
+	"strconv"
+)
+
+// Hex ...
+func Hex(args ...object.Object) object.Object {
+	if len(args) != 1 {
+		return newError("wrong number of arguments. got=%d, want=1",
+			len(args))
+	}
+
+	if i, ok := args[0].(*object.Integer); ok {
+		return &object.String{Value: fmt.Sprintf("0x%s", strconv.FormatInt(i.Value, 16))}
+	}
+	return newError("argument to `hex` not supported, got %s", args[0].Type())
+}
diff --git a/builtins/id.go b/builtins/id.go
new file mode 100644
index 0000000..7214ac0
--- /dev/null
+++ b/builtins/id.go
@@ -0,0 +1,38 @@
+package builtins
+
+import (
+	"fmt"
+	"monkey/object"
+)
+
+// IdOf ...
+func IdOf(args ...object.Object) object.Object {
+	if len(args) != 1 {
+		return newError("wrong number of arguments. got=%d, want=1",
+			len(args))
+	}
+
+	arg := args[0]
+
+	if n, ok := arg.(*object.Null); ok {
+		return &object.String{Value: fmt.Sprintf("%p", n)}
+	} else if b, ok := arg.(*object.Boolean); ok {
+		return &object.String{Value: fmt.Sprintf("%p", b)}
+	} else if i, ok := arg.(*object.Integer); ok {
+		return &object.String{Value: fmt.Sprintf("%p", i)}
+	} else if s, ok := arg.(*object.String); ok {
+		return &object.String{Value: fmt.Sprintf("%p", s)}
+	} else if a, ok := arg.(*object.Array); ok {
+		return &object.String{Value: fmt.Sprintf("%p", a)}
+	} else if h, ok := arg.(*object.Hash); ok {
+		return &object.String{Value: fmt.Sprintf("%p", h)}
+	} else if f, ok := arg.(*object.Function); ok {
+		return &object.String{Value: fmt.Sprintf("%p", f)}
+	} else if c, ok := arg.(*object.Closure); ok {
+		return &object.String{Value: fmt.Sprintf("%p", c)}
+	} else if b, ok := arg.(*object.Builtin); ok {
+		return &object.String{Value: fmt.Sprintf("%p", b)}
+	} else {
+		return newError("argument 31 to `id()` unsupported got=%T", arg.Type())
+	}
+}
diff --git a/builtins/oct.go b/builtins/oct.go
new file mode 100644
index 0000000..e107ad8
--- /dev/null
+++ b/builtins/oct.go
@@ -0,0 +1,20 @@
+package builtins
+
+import (
+	"fmt"
+	"monkey/object"
+	"strconv"
+)
+
+// Oct ...
+func Oct(args ...object.Object) object.Object {
+	if len(args) != 1 {
+		return newError("wrong number of arguments. got=%d, want=1",
+			len(args))
+	}
+
+	if i, ok := args[0].(*object.Integer); ok {
+		return &object.String{Value: fmt.Sprintf("0%s", strconv.FormatInt(i.Value, 8))}
+	}
+	return newError("argument to `oct` not supported, got %s", args[0].Type())
+}
diff --git a/builtins/ord.go b/builtins/ord.go
new file mode 100644
index 0000000..0dc21f4
--- /dev/null
+++ b/builtins/ord.go
@@ -0,0 +1,19 @@
+package builtins
+
+import "monkey/object"
+
+// Ord ...
+func Ord(args ...object.Object) object.Object {
+	if len(args) != 1 {
+		return newError("wrong number of arguments. got=%d, want=1",
+			len(args))
+	}
+
+	if s, ok := args[0].(*object.String); ok {
+		if len(s.Value) == 1 {
+			return &object.Integer{Value: int64(s.Value[0])}
+		}
+		return newError("`ord()` expected a character but got string of length %d", len(s.Value))
+	}
+	return newError("argument to `ord` not supported, got %s", args[0].Type())
+}
diff --git a/builtins/pow.go b/builtins/pow.go
new file mode 100644
index 0000000..63f02c8
--- /dev/null
+++ b/builtins/pow.go
@@ -0,0 +1,34 @@
+package builtins
+
+import "monkey/object"
+
+func pow(x, y int64) int64 {
+	p := int64(1)
+	for y > 0 {
+		if y&1 != 0 {
+			p *= x
+		}
+		y >>= 1
+		x *= x
+	}
+	return p
+}
+
+// Pow ...
+func Pow(args ...object.Object) object.Object {
+	if len(args) != 2 {
+		return newError("wrong number of arguments. got=%d, want=2",
+			len(args))
+	}
+
+	if x, ok := args[0].(*object.Integer); ok {
+		if y, ok := args[1].(*object.Integer); ok {
+			value := pow(x.Value, y.Value)
+			return &object.Integer{Value: value}
+		} else {
+			return newError("expected argument #2 to `pow` to be `int` got=%s", args[1].Type())
+		}
+	} else {
+		return newError("expected argument #1 to `pow` to be `int` got=%s", args[0].Type())
+	}
+}
diff --git a/compiler/compiler_test.go b/compiler/compiler_test.go
index cc920dc..f030019 100644
--- a/compiler/compiler_test.go
+++ b/compiler/compiler_test.go
@@ -879,11 +879,11 @@ func TestBuiltins(t *testing.T) {
             `,
 			expectedConstants: []interface{}{1},
 			expectedInstructions: []code.Instructions{
-				code.Make(code.OpGetBuiltin, 11),
+				code.Make(code.OpGetBuiltin, 18),
 				code.Make(code.OpArray, 0),
 				code.Make(code.OpCall, 1),
 				code.Make(code.OpPop),
-				code.Make(code.OpGetBuiltin, 15),
+				code.Make(code.OpGetBuiltin, 25),
 				code.Make(code.OpArray, 0),
 				code.Make(code.OpConstant, 0),
 				code.Make(code.OpCall, 2),
@@ -894,7 +894,7 @@ func TestBuiltins(t *testing.T) {
 			input: `fn() { return len([]) }`,
 			expectedConstants: []interface{}{
 				[]code.Instructions{
-					code.Make(code.OpGetBuiltin, 11),
+					code.Make(code.OpGetBuiltin, 18),
 					code.Make(code.OpArray, 0),
 					code.Make(code.OpCall, 1),
 					code.Make(code.OpReturn),