docs: fix minor typos

subjects/java/checkpoints/average-calc/README.md

@@ -2,7 +2,7 @@
 
 ### Instructions
 
-Write a function named `average` in a file named `AverageCalc` java. This function takes three parameters: start, end, and step. It returns the average of the numbers between start and end with each number being greater than the previous one by the step given."
+Write a function named `average` in a file named `AverageCalc` java. This function takes three parameters: start, end, and step. It returns the average of the numbers between start and end with each number being greater than the previous one by the step given.
 
 ### Expected Functions
 
@@ -21,7 +21,7 @@ Here is a possible `ExerciseRunner.java` to test your function :
 ```java
 public class ExerciseRunner {
     public static void main(String[] args) {
-        System.out.println(MultiplicationTable.generate(1,5,1));
+        System.out.println(AverageCalc.average(1,5,1));
     }
 }
 ```