diff --git a/basic-geometry/dual-number.c b/basic-geometry/dual-number.c
index d8fd6bf..1d39f5b 100644
--- a/basic-geometry/dual-number.c
+++ b/basic-geometry/dual-number.c
@@ -21,11 +21,17 @@ extern inline void bgc_fp64_dual_number_add_scaled(BGC_FP64_DualNumber* sum, con
 extern inline void bgc_fp32_dual_number_subtract(BGC_FP32_DualNumber* difference, const BGC_FP32_DualNumber* minuend, const BGC_FP32_DualNumber* subtrahend);
 extern inline void bgc_fp64_dual_number_subtract(BGC_FP64_DualNumber* difference, const BGC_FP64_DualNumber* minuend, const BGC_FP64_DualNumber* subtrahend);
 
-extern inline void bgc_fp32_dual_number_multiply(BGC_FP32_DualNumber* product, const BGC_FP32_DualNumber* multiplicand, const float multiplier);
-extern inline void bgc_fp64_dual_number_multiply(BGC_FP64_DualNumber* product, const BGC_FP64_DualNumber* multiplicand, const double multiplier);
+extern inline void bgc_fp32_dual_number_multiply_by_real_number(BGC_FP32_DualNumber* product, const BGC_FP32_DualNumber* multiplicand, const float multiplier);
+extern inline void bgc_fp64_dual_number_multiply_by_real_number(BGC_FP64_DualNumber* product, const BGC_FP64_DualNumber* multiplicand, const double multiplier);
 
-extern inline void bgc_fp32_dual_number_divide(BGC_FP32_DualNumber* quotient, const BGC_FP32_DualNumber* dividend, const float divisor);
-extern inline void bgc_fp64_dual_number_divide(BGC_FP64_DualNumber* quotient, const BGC_FP64_DualNumber* dividend, const double divisor);
+extern inline void bgc_fp32_dual_number_multiply_by_dual_number(BGC_FP32_DualNumber* product, const BGC_FP32_DualNumber* first, const BGC_FP32_DualNumber* second);
+extern inline void bgc_fp64_dual_number_multiply_by_dual_number(BGC_FP64_DualNumber* product, const BGC_FP64_DualNumber* first, const BGC_FP64_DualNumber* second);
+
+extern inline void bgc_fp32_dual_number_divide_by_real_number(BGC_FP32_DualNumber* quotient, const BGC_FP32_DualNumber* dividend, const float divisor);
+extern inline void bgc_fp64_dual_number_divide_by_real_number(BGC_FP64_DualNumber* quotient, const BGC_FP64_DualNumber* dividend, const double divisor);
+
+extern inline void bgc_fp32_dual_number_divide_by_dual_number(BGC_FP32_DualNumber* quotient, const BGC_FP32_DualNumber* dividend, const BGC_FP32_DualNumber* divisor);
+extern inline void bgc_fp64_dual_number_divide_by_dual_number(BGC_FP64_DualNumber* quotient, const BGC_FP64_DualNumber* dividend, const BGC_FP64_DualNumber* divisor);
 
 extern inline void bgc_fp32_dual_number_get_mean2(BGC_FP32_DualNumber* mean, const BGC_FP32_DualNumber* first, const BGC_FP32_DualNumber* second);
 extern inline void bgc_fp64_dual_number_get_mean2(BGC_FP64_DualNumber* mean, const BGC_FP64_DualNumber* first, const BGC_FP64_DualNumber* second);
diff --git a/basic-geometry/dual-number.h b/basic-geometry/dual-number.h
index f1a4e2a..392e9c5 100644
--- a/basic-geometry/dual-number.h
+++ b/basic-geometry/dual-number.h
@@ -113,28 +113,56 @@ inline void bgc_fp64_dual_number_subtract(BGC_FP64_DualNumber* difference, const
 
 // ================== Multiply ================== //
 
-inline void bgc_fp32_dual_number_multiply(BGC_FP32_DualNumber* product, const BGC_FP32_DualNumber* multiplicand, const float multiplier)
+inline void bgc_fp32_dual_number_multiply_by_real_number(BGC_FP32_DualNumber* product, const BGC_FP32_DualNumber* multiplicand, const float multiplier)
 {
     product->real = multiplicand->real * multiplier;
     product->dual = multiplicand->dual * multiplier;
 }
 
-inline void bgc_fp64_dual_number_multiply(BGC_FP64_DualNumber* product, const BGC_FP64_DualNumber* multiplicand, const double multiplier)
+inline void bgc_fp64_dual_number_multiply_by_real_number(BGC_FP64_DualNumber* product, const BGC_FP64_DualNumber* multiplicand, const double multiplier)
 {
     product->real = multiplicand->real * multiplier;
     product->dual = multiplicand->dual * multiplier;
 }
 
+inline void bgc_fp32_dual_number_multiply_by_dual_number(BGC_FP32_DualNumber* product, const BGC_FP32_DualNumber* first, const BGC_FP32_DualNumber* second)
+{
+    product->real = first->real * second->real;
+    product->dual = first->dual * second->real + first->real * second->dual;
+}
+
+inline void bgc_fp64_dual_number_multiply_by_dual_number(BGC_FP64_DualNumber* product, const BGC_FP64_DualNumber* first, const BGC_FP64_DualNumber* second)
+{
+    product->real = first->real * second->real;
+    product->dual = first->dual * second->real + first->real * second->dual;
+}
+
 // =================== Divide =================== //
 
-inline void bgc_fp32_dual_number_divide(BGC_FP32_DualNumber* quotient, const BGC_FP32_DualNumber* dividend, const float divisor)
+inline void bgc_fp32_dual_number_divide_by_real_number(BGC_FP32_DualNumber* quotient, const BGC_FP32_DualNumber* dividend, const float divisor)
 {
-    bgc_fp32_dual_number_multiply(quotient, dividend, 1.0f / divisor);
+    bgc_fp32_dual_number_multiply_by_real_number(quotient, dividend, 1.0f / divisor);
 }
 
-inline void bgc_fp64_dual_number_divide(BGC_FP64_DualNumber* quotient, const BGC_FP64_DualNumber* dividend, const double divisor)
+inline void bgc_fp64_dual_number_divide_by_real_number(BGC_FP64_DualNumber* quotient, const BGC_FP64_DualNumber* dividend, const double divisor)
 {
-    bgc_fp64_dual_number_multiply(quotient, dividend, 1.0 / divisor);
+    bgc_fp64_dual_number_multiply_by_real_number(quotient, dividend, 1.0 / divisor);
+}
+
+inline void bgc_fp32_dual_number_divide_by_dual_number(BGC_FP32_DualNumber* quotient, const BGC_FP32_DualNumber* dividend, const BGC_FP32_DualNumber* divisor)
+{
+    const float mutliplier_real = 1 / divisor->real;
+
+    quotient->real = dividend->real * mutliplier_real;
+    quotient->dual = dividend->dual * mutliplier_real - dividend->real * divisor->dual / (divisor->real * divisor->real);
+}
+
+inline void bgc_fp64_dual_number_divide_by_dual_number(BGC_FP64_DualNumber* quotient, const BGC_FP64_DualNumber* dividend, const BGC_FP64_DualNumber* divisor)
+{
+    const double mutliplier_real = 1 / divisor->real;
+
+    quotient->real = dividend->real * mutliplier_real;
+    quotient->dual = dividend->dual * mutliplier_real - dividend->real * divisor->dual / (divisor->real * divisor->real);
 }
 
 // ================ Mean of Two ================= //