diff --git a/intro_lab/README.md b/intro_lab/README.md
index a3644dbe6f847cb7a94e9a30db176c3c5d28d73e..8152b147d9bf925acac196c12fdedc5824dda10d 100644
--- a/intro_lab/README.md
+++ b/intro_lab/README.md
@@ -94,7 +94,7 @@ Questions:
 - How many different ways are there to change the number of threads? Which one are those?
 - How can you make the output ordered from thread 0 to thread 4?
 
-## Exercise 2 - Creating Threads: calculate π in parallel using only pragma omp parallel
+## Exercise 2 - Creating Threads: calculate π in parallel using pragma omp parallel
 
 _Concepts: Parallel, default data environment, runtime library calls_
 
@@ -213,15 +213,15 @@ Questions:
 - What would happen if you hadn’t used critical or atomic a shared variable?
 - How does the execution time change varying the number of threads? Is it what
   you expected?
-- Do the two version of the codes differ in performance? If so, what do you
-  think it is the reason?
+- Do the two versions of the code differ in performance? If so, what do you
+  think is the reason?
 
 ## Exercise 4 - Calculate π with a loop and a reduction
 
 _Concepts: worksharing, parallel loop, schedule, reduction_
 
 Here we are going to implement a fourth parallel version of the pi.c / pi.f90
-code to calculate the value of π using omp for and reduction operations.
+code to calculate the value of π using ``omp for`` and ``reduction`` operations.
 
 Instructions: Create a new parallel versions of the pi.c / pi.f90 program using
 the parallel construct ``#pragma omp for`` and ``reduction`` operation. Run the new
@@ -231,7 +231,7 @@ the execution time for 1, 2, 4, 8, 16, 32 threads.
 
 Hints:
 
-To change the schedule, you can either change the environment variable with
+- To change the schedule, you can either change the environment variable with
 ``export OMP_SCHEDULE=type`` where ``type`` can be any of static, dynamic, guided or in
 the source code as ``omp parallel for schedule(type)``.
 
@@ -239,5 +239,5 @@ Questions:
 
 - What is the scheduling that provides the best performance? What is the reason for that?
 - What is the fastest parallel implementation of pi.c / pi.f90 program? What is
-  the reason for being the fastest? What would be an even faster implementation
+  the reason for it being the fastest? What would be an even faster implementation
   of pi.c / pi.f90 program?
diff --git a/intro_lab/hello.c b/intro_lab/hello.c
index 04a6c145b2cfeb1dc4dd93f3751e2d991ac8bda8..9cdc610c2107b6911af1be807e5b10adc727d59d 100644
--- a/intro_lab/hello.c
+++ b/intro_lab/hello.c
@@ -1,7 +1,8 @@
 #include <stdio.h>
+
 int main ()
 {
-  int ID = 0; // thread id
+    int thread_id = 0;
 
-  printf("Hello World from thread %d \n", ID);
+    printf("Hello World from thread %d \n", thread_id);
 }
diff --git a/intro_lab/pi.c b/intro_lab/pi.c
index b3a66fe4bc6e2cfbea800aee47c366862a4dfae0..8bcfe7e134930e0bd1179742b4cc6e6db16437af 100644
--- a/intro_lab/pi.c
+++ b/intro_lab/pi.c
@@ -3,7 +3,7 @@
 This program will numerically compute the integral of
 
                   4/(1+x*x) 
-				  
+
 from 0 to 1.  The value of this integral is pi -- which 
 is great since it gives us an easy way to check the answer.
 
@@ -13,32 +13,29 @@ from the OpenMP runtime library
 History: Written by Tim Mattson, 11/99.
 
 */
+
 #include <stdio.h>
 #include <omp.h>
+
 static long num_steps = 100000000;
 double step;
+
 int main ()
 {
-	  int i;
-	  double x, pi, sum = 0.0;
-	  double start_time, run_time;
-
-	  step = 1.0/(double) num_steps;
-
-        	 
-	  start_time = omp_get_wtime();
-
-	  for (i=1;i<= num_steps; i++){
-		  x = (i-0.5)*step;
-		  sum = sum + 4.0/(1.0+x*x);
-	  }
-
-	  pi = step * sum;
-	  run_time = omp_get_wtime() - start_time;
-	  printf("\n pi with %ld steps is %lf in %lf seconds\n ",num_steps,pi,run_time);
-}	  
-
+    int i;
+    double x, pi, sum = 0.0;
+    double start_time, run_time;
 
+    step = 1.0/(double) num_steps;
 
+    start_time = omp_get_wtime();
 
+    for (i=1;i<= num_steps; i++){
+        x = (i-0.5)*step;
+        sum = sum + 4.0/(1.0+x*x);
+    }
 
+    pi = step * sum;
+    run_time = omp_get_wtime() - start_time;
+    printf("\n pi with %ld steps is %lf in %lf seconds\n ",num_steps,pi,run_time);
+}