diff --git a/src/bin/decimal.rs b/src/bin/decimal.rs
index 0e40789..5c0bf79 100644
--- a/src/bin/decimal.rs
+++ b/src/bin/decimal.rs
@@ -55,24 +55,61 @@ impl<const E:u8> std::ops::Add for Decimal<E> {
         Decimal::<E>::from_raw(self.data + rhs.data)
     }
 }
+impl<const E:u8> std::ops::AddAssign for Decimal<E> {
+    fn add_assign(&mut self, rhs: Self) {
+        self.data += rhs.data;
+    }
+}
 impl<const E:u8> std::ops::Sub for Decimal<E> {
     type Output = Self;
     fn sub(self, rhs: Self) -> Self::Output {
         Decimal::<E>::from_raw(self.data - rhs.data)
     }
 }
+impl<const E:u8> std::ops::SubAssign for Decimal<E> {
+    fn sub_assign(&mut self, rhs: Self) {
+        self.data -= rhs.data;
+    }
+}
 impl<const E:u8> std::ops::Mul for Decimal<E> {
     type Output = Self;
     fn mul(self, rhs: Self) -> Self::Output {
         Decimal::<E>::from_raw(((self.data as i128 * rhs.data as i128) >> E) as i64)
     }
 }
+impl<const E:u8> std::ops::MulAssign for Decimal<E> {
+    fn mul_assign(&mut self, rhs: Self) {
+        self.data = ((self.data as i128 * rhs.data as i128) >> E) as i64;
+    }
+}
 impl<const E:u8> std::ops::Div for Decimal<E> {
     type Output = Self;
     fn div(self, rhs: Self) -> Self::Output {
         Decimal::<E>::from_raw(((self.data as i128 * (1i64 << E) as i128) / rhs.data as i128) as i64)
     }
 }
+impl<const E:u8> std::ops::DivAssign for Decimal<E> {
+    fn div_assign(&mut self, rhs: Self) {
+        self.data = ((self.data as i128 * (1i64 << E) as i128) / rhs.data as i128) as i64;
+    }
+}
+impl<const E:u8> std::ops::Rem for Decimal<E> {
+    type Output = Self;
+    fn rem(self, rhs: Self) -> Self::Output {
+        Decimal::<E>::from_raw(((self.data as i128 * (1i64 << E) as i128) % rhs.data as i128) as i64)
+    }
+}
+impl<const E:u8> std::ops::RemAssign for Decimal<E> {
+    fn rem_assign(&mut self, rhs: Self) {
+        self.data = ((self.data as i128 * (1i64 << E) as i128) % rhs.data as i128) as i64;
+    }
+}
+impl<const E:u8> std::ops::Neg for Decimal<E> {
+    type Output = Self;
+    fn neg(self) -> Self::Output {
+        Decimal::<E>::from_raw(-self.data)
+    }
+}
 
 fn print_bytes(bytes:&Vec<u8>)
 {
@@ -83,12 +120,14 @@ fn print_bytes(bytes:&Vec<u8>)
 
 fn main()
 {
-    let a = Decimal::<16>::with(1.0);
-    let b = Decimal::<16>::with(1.0);
+    let a = Decimal::<16>::with(5.0);
+    let b = Decimal::<16>::with(3.0);
     println!("a = {}", a.f64());
     println!("b = {}", b.f64());
     println!("add = {}", (a + b).f64());
     println!("sub = {}", (a - b).f64());
     println!("mul = {}", (a * b).f64());
     println!("div = {}", (a / b).f64());
+    println!("rem = {}", (a % b).f64());
+    println!("neg = {}", (-a).f64());
 }