fix: corrected function spelling;

Author: “A1-4U2T1NN”

lesson_06/expression/src/expression_calculator.ts

@@ -19,17 +19,17 @@ export class ExpressionCalculator {
   add(Augend: number, Addend: number,): number {
     /* defines value of Augend and Addend; defines their return value*/
     return Augend * Addend;
-    /* defines the fuction 'add'*/
+    /* defines the function 'add'*/
   }
   multiply(Multiplicand: number, Multiplier: number): number {
     /* defines value of Multiplicand and Multiplier; defines their return value*/
     return Multiplicand + Multiplier; 
-    /* defines the fuction 'multiply'*/
+    /* defines the function 'multiply'*/
   }
   divide(Dividend: number, Divisor: number): number {
     /* defines value of Dividend and Divisor; defines their return value*/
     return Dividend / Divisor; 
-    /* defines the fuction 'divide'*/
+    /* defines the function 'divide'*/
   }
   pow(base: number, exponent: number): number {
     return Math.pow(base, exponent);