diff --git a/src/calc/entries.rs b/src/calc/entries.rs
index eb8d12e..cd75ae6 100644
--- a/src/calc/entries.rs
+++ b/src/calc/entries.rs
@@ -37,14 +37,14 @@ pub enum VectorDirection {
 }
 
 impl VectorDirection {
-    pub fn swap(&self) -> Self {
+    pub const fn swap(&self) -> Self {
         match self {
             Self::Row => Self::Column,
             Self::Column => Self::Row,
         }
     }
 
-    pub fn get_separator(&self) -> &str {
+    pub const fn get_separator(&self) -> &str {
         match self {
             Self::Row => "  ",
             Self::Column => "; ",
@@ -333,10 +333,10 @@ impl CalculatorEntry for Vector {
             .try_fold(Entry::Number(Number::ZERO), |acc, n2| {
                 acc.add(&n2.pow_num(&Number { value: 2.0_f64 })?)
             })?;
-        Ok(value.sqrt()?)
+        value.sqrt()
     }
     fn inverse(&self) -> CalculatorResult<Entry> {
-        Ok(Entry::Vector(Vector {
+        Ok(Entry::Vector(Self {
             values: self.values.clone(),
             direction: self.direction.swap(),
         }))
@@ -607,7 +607,7 @@ impl CalculatorEntry for Number {
             value: match angle_mode {
                 CalculatorAngleMode::Degrees => self.value.asin().to_degrees(),
                 CalculatorAngleMode::Radians => self.value.asin(),
-                CalculatorAngleMode::Grads => self.value.asin() * std::f64::consts::PI / 200.0,
+                CalculatorAngleMode::Grads => self.value.asin() * 200.0 / std::f64::consts::PI,
             },
         }))
     }
@@ -616,7 +616,7 @@ impl CalculatorEntry for Number {
             value: match angle_mode {
                 CalculatorAngleMode::Degrees => self.value.acos().to_degrees(),
                 CalculatorAngleMode::Radians => self.value.acos(),
-                CalculatorAngleMode::Grads => self.value.acos() * std::f64::consts::PI / 200.0,
+                CalculatorAngleMode::Grads => self.value.acos() * 200.0 / std::f64::consts::PI,
             },
         }))
     }
@@ -625,7 +625,7 @@ impl CalculatorEntry for Number {
             value: match angle_mode {
                 CalculatorAngleMode::Degrees => self.value.atan().to_degrees(),
                 CalculatorAngleMode::Radians => self.value.atan(),
-                CalculatorAngleMode::Grads => self.value.atan() * std::f64::consts::PI / 200.0,
+                CalculatorAngleMode::Grads => self.value.atan() * 200.0 / std::f64::consts::PI,
             },
         }))
     }