diff --git a/src/data_types/array.rs b/src/data_types/array.rs
index 39d8ae4..f50bb6e 100644
--- a/src/data_types/array.rs
+++ b/src/data_types/array.rs
@@ -9,8 +9,8 @@ use crate::token::Literals;
 impl DoveObject for Rc<RefCell<Vec<Literals>>> {
     fn get_property(&mut self, name: &str) -> Result<Literals> {
         match name {
-            "length" => Ok(Literals::Number(self.borrow().len() as f64)),
-            "empty" => Ok(Literals::Boolean(self.borrow().len() == 0)),
+            "len" => Ok(Literals::Function(Rc::new(array_len(self)))),
+            "is_empty" => Ok(Literals::Function(Rc::new(array_is_empty(self)))),
             "push" => Ok(Literals::Function(Rc::new(array_append(self)))),
             "pop" => Ok(Literals::Function(Rc::new(array_pop(self)))),
             "remove" => Ok(Literals::Function(Rc::new(array_remove(self)))),
@@ -19,6 +19,22 @@ impl DoveObject for Rc<RefCell<Vec<Literals>>> {
     }
 }
 
+fn array_len(array: &Rc<RefCell<Vec<Literals>>>) -> impl DoveCallable {
+    let array = Rc::clone(array);
+
+    BuiltinFunction::new(0, move |_| {
+        Ok(Literals::Number(array.borrow().len() as f64))
+    })
+}
+
+fn array_is_empty(array: &Rc<RefCell<Vec<Literals>>>) -> impl DoveCallable {
+    let array = Rc::clone(array);
+
+    BuiltinFunction::new(0, move |_| {
+        Ok(Literals::Boolean(array.borrow().len() == 0))
+    })
+}
+
 fn array_append(array: &Rc<RefCell<Vec<Literals>>>) -> impl DoveCallable {
     let array = Rc::clone(array);
 
diff --git a/src/data_types/dict.rs b/src/data_types/dict.rs
index 0bff91f..1912463 100644
--- a/src/data_types/dict.rs
+++ b/src/data_types/dict.rs
@@ -10,7 +10,7 @@ use crate::token::{Literals, DictKey};
 impl DoveObject for Rc<RefCell<HashMap<DictKey, Literals>>> {
     fn get_property(&mut self, name: &str) -> Result<Literals> {
         match name {
-            "length" => Ok(Literals::Number(self.borrow().len() as f64)),
+            "len" => Ok(Literals::Function(Rc::new(dict_len(self)))),
             "keys" => Ok(Literals::Function(Rc::new(dict_keys(self)))),
             "values" => Ok(Literals::Function(Rc::new(dict_values(self)))),
             "remove" => Ok(Literals::Function(Rc::new(dict_remove(self)))),
@@ -19,6 +19,14 @@ impl DoveObject for Rc<RefCell<HashMap<DictKey, Literals>>> {
     }
 }
 
+fn dict_len(dict: &Rc<RefCell<HashMap<DictKey, Literals>>>) -> impl DoveCallable {
+    let dict = Rc::clone(dict);
+
+    BuiltinFunction::new(0, move |_| {
+        Ok(Literals::Number(dict.borrow().len() as f64))
+    })
+}
+
 fn dict_keys(dict: &Rc<RefCell<HashMap<DictKey, Literals>>>) -> impl DoveCallable {
     let dict = Rc::clone(dict);
 
diff --git a/src/data_types/mod.rs b/src/data_types/mod.rs
index 5baf9bd..c793a2f 100644
--- a/src/data_types/mod.rs
+++ b/src/data_types/mod.rs
@@ -1,5 +1,6 @@
 use crate::token::Literals;
 
+pub mod number;
 pub mod string;
 pub mod array;
 pub mod dict;
diff --git a/src/data_types/number.rs b/src/data_types/number.rs
new file mode 100644
index 0000000..7fbcd80
--- /dev/null
+++ b/src/data_types/number.rs
@@ -0,0 +1,42 @@
+use std::rc::Rc;
+
+use crate::data_types::*;
+use crate::dove_callable::{DoveCallable, BuiltinFunction};
+use crate::token::Literals;
+
+impl DoveObject for f64 {
+    fn get_property(&mut self, name: &str) -> Result<Literals> {
+        match name {
+            "fract" => Ok(Literals::Function(Rc::new(number_fract(*self)))),
+            "abs" => Ok(Literals::Function(Rc::new(number_abs(*self)))),
+            "floor" => Ok(Literals::Function(Rc::new(number_floor(*self)))),
+            "ceil" => Ok(Literals::Function(Rc::new(number_ceil(*self)))),
+            _ => Err(Error::CannotGetProperty),
+        }
+    }
+}
+
+fn number_fract(number: f64) -> impl DoveCallable {
+    BuiltinFunction::new(0, move |_| {
+        Ok(Literals::Number(number.fract()))
+    })
+}
+
+fn number_abs(number: f64) -> impl DoveCallable {
+    BuiltinFunction::new(0, move |_| {
+        Ok(Literals::Number(number.abs()))
+    })
+}
+
+fn number_floor(number: f64) -> impl DoveCallable {
+    BuiltinFunction::new(0, move |_| {
+        Ok(Literals::Number(number.floor()))
+    })
+}
+
+fn number_ceil(number: f64) -> impl DoveCallable {
+    BuiltinFunction::new(0, move |_| {
+        Ok(Literals::Number(number.ceil()))
+    })
+}
+
diff --git a/src/data_types/string.rs b/src/data_types/string.rs
index a8059bf..4f817ab 100644
--- a/src/data_types/string.rs
+++ b/src/data_types/string.rs
@@ -8,14 +8,21 @@ use crate::token::Literals;
 impl DoveObject for String {
     fn get_property(&mut self, name: &str) -> Result<Literals> {
         match name {
-            "length" => Ok(Literals::Number(self.len() as f64)),
-            // "chars" => Ok(Literals::Function(Rc::new(StringChars { string: self.clone() }))),
+            "len" => Ok(Literals::Function(Rc::new(string_len(self)))),
             "chars" => Ok(Literals::Function(Rc::new(string_chars(self)))),
             _ => Err(Error::CannotGetProperty),
         }
     }
 }
 
+fn string_len(string: &str) -> impl DoveCallable {
+    let string = string.to_string();
+
+    BuiltinFunction::new(0, move |_| {
+        Ok(Literals::Number(string.len() as f64))
+    })
+}
+
 fn string_chars(string: &str) -> impl DoveCallable {
     let string = string.to_string();
 
diff --git a/src/token.rs b/src/token.rs
index d2aa0ad..e6d9108 100644
--- a/src/token.rs
+++ b/src/token.rs
@@ -124,6 +124,7 @@ impl Literals {
 
     pub fn as_object(&self) -> Box<dyn DoveObject> {
         match self {
+            Literals::Number(number) => Box::new(*number),
             Literals::String(string) => Box::new(string.clone()),
             Literals::Instance(instance) => Box::new(Rc::clone(instance)),
             Literals::Array(array) => Box::new(Rc::clone(array)),