diff --git a/laborator/content/reprezentare-numere/1-convert/convert.txt b/laborator/content/reprezentare-numere/1-convert/convert.txt
new file mode 100644
index 00000000..a1c3e037
--- /dev/null
+++ b/laborator/content/reprezentare-numere/1-convert/convert.txt
@@ -0,0 +1,44 @@
+a.
+121 / 2 = 60  r1
+60 / 2 = 30 r0
+30 / 2 = 15 r0
+15 / 2 = 7 r1
+7 / 2 = 3 r1
+3 / 2 = 1 r1
+1 / 2 = 0 r1
+
+121 = 0b 0111 1001
+    = 0x79
+
+
+
+18446 / 2 = 9223 r0
+9223 / 2 = 4611 r1
+4611 / 2 = 2305 r1
+2305 / 2 = 1152 r1
+1152 / 2 = 576 r0
+576 / 2 = 288 r0
+288 / 2 = 144 r0
+144 / 2 = 72 r0
+72 / 2 = 36 r0
+36 / 2 = 18 r0
+18 / 2 = 9 r0
+9 / 2 = 4 r1
+4 / 2 = 2 r0
+2 / 2 = 1 r0
+1 / 2 = 0 r1
+
+18446 = 0b0100 1000 0000 1110
+      = 0x480E
+
+b.
+50642
+47913
+
+c.
+0b1011110
+0b100101000000001
+
+d.
+0x7d
+0x8c1f
\ No newline at end of file
diff --git a/laborator/content/reprezentare-numere/2-len_xor/len_xor.c b/laborator/content/reprezentare-numere/2-len_xor/len_xor.c
index 8e45ecbd..09ec009f 100644
--- a/laborator/content/reprezentare-numere/2-len_xor/len_xor.c
+++ b/laborator/content/reprezentare-numere/2-len_xor/len_xor.c
@@ -2,31 +2,36 @@
 #include <stdlib.h>
 #include <string.h>
 
-int my_strlen(const char *str)
-{
-	/* TODO */
-
-	/**
-	 * The cast to (void) is used to avoid a compiler warning. Remove the line
-	 * below to find out what the warning is.
-	 *
-	 * Remove this cast when implementing the function.
-	 */
-	(void) str;
-
-	return -1;
+int my_strlen(const char *str) {
+  int len = 0;
+  while (*str) {
+    len++;
+    str++;
+  }
+  return len - 1;
 }
 
-void equality_check(const char *str)
-{
-	/* TODO */
-	(void) str;
+void equality_check(const char *str, int l) {
+  int i, I;
+  for (i = 0; i < l; i++) {
+    I = i + (1 << i);
+    if (I > l) {
+      if (*(str + i) % *(str + I))
+        printf("Address of %c: %p\n", *(str + i), (str + i));
+    } else if (*(str + i) ^ *(str + I))
+      printf("Address of %c: %p\n", *(str + i), (str + i));
+  }
 }
 
-int main(void)
-{
-	/* TODO: Test functions */
+int main(void) {
+  char s[100];
+  int l;
 
-	return 0;
-}
+  fgets(s, 100, stdin);
+  l = my_strlen(s);
 
+  printf("length = %d\n", l);
+  equality_check(s, l);
+
+  return 0;
+}
diff --git a/laborator/content/reprezentare-numere/3-mirror/mirror.c b/laborator/content/reprezentare-numere/3-mirror/mirror.c
index 513c0ab4..ade5bf92 100644
--- a/laborator/content/reprezentare-numere/3-mirror/mirror.c
+++ b/laborator/content/reprezentare-numere/3-mirror/mirror.c
@@ -2,16 +2,26 @@
 #include <stdlib.h>
 #include <string.h>
 
-void mirror(char *s)
-{
-	/* TODO */
-	(void) s;
+void mirror(char *s) {
+  int l = strlen(s), i, j;
+  i = 0;
+  j = l - 1;
+
+  char aux;
+  while (i < j) {
+    aux = *(s + i);
+    *(s + i) = *(s + j);
+    *(s + j) = aux;
+    i++;
+    j--;
+  }
 }
 
-int main(void)
-{
-	/* TODO: Test function */
+int main(void) {
+  char sir[] = "Ana n-are mere";
 
-	return 0;
-}
+  mirror(sir);
+  puts(sir);
 
+  return 0;
+}
\ No newline at end of file