diff --git a/cpp/dziesietna_na_osemkowa/main.cpp b/cpp/dziesietna_na_osemkowa/main.cpp
new file mode 100644
index 0000000..519439c
--- /dev/null
+++ b/cpp/dziesietna_na_osemkowa/main.cpp
@@ -0,0 +1,40 @@
+#include <iostream>
+using namespace std;
+
+int main() {
+    int i,k,n,m;
+
+    cout << "Podaj liczbe dziesietna: ";
+    cin >> n;
+    int *a = new int[n];
+    
+    m=n;
+
+    i = 1;
+    while(m>=1) {
+        a[i] = m % 8;
+        cout << a[i] << " ";
+        m = m / 8;
+        i++;
+    }
+
+    k = i - 1;
+
+    cout << endl << "K = " << k << endl;
+
+    for(i = 1; i <= k; i++) {
+        if(i % 3 == 0) {
+            cout << " " << a[i];
+        }
+        else {
+            cout << a[i];
+        }
+    }
+
+    cout << endl;
+
+    delete [] a;
+
+    system("pause");
+    return 0;
+}
\ No newline at end of file
diff --git a/cpp/dziesietna_na_osemkowa/main.py b/cpp/dziesietna_na_osemkowa/main.py
new file mode 100644
index 0000000..90fe16e
--- /dev/null
+++ b/cpp/dziesietna_na_osemkowa/main.py
@@ -0,0 +1,21 @@
+def main():
+    liczba_dziesietna = int(input("Podaj liczbę dziesiętną: "))
+
+    m = liczba_dziesietna
+    i = 1
+    a = liczba_dziesietna
+
+    while m >= 1:
+        a[i] = m % 8
+        print(a[i], end=" ")
+        m = m / 8
+        i += 1
+    
+    k = i - 1
+
+    print("\nLiczba w systemie 8-cyfrowym: ", end="")
+    while k >= 1:
+        print(a[k], end="")
+        k += 1
+
+    print("\n")
diff --git a/cpp/system10-16/main.cpp b/cpp/system10-16/main.cpp
new file mode 100644
index 0000000..d15af55
--- /dev/null
+++ b/cpp/system10-16/main.cpp
@@ -0,0 +1,60 @@
+#include <iostream>
+using namespace std;
+
+int main() {
+    int i,k,n,m;
+
+    cout << "Podaj liczbe dziesietna: ";
+    cin >> n;
+    int *a = new int[n];
+    
+    m=n;
+
+    i = 1;
+    while(m>=1) {
+        a[i] = m % 16;
+        m = m / 16;
+        i++;
+    }
+
+    k = i - 1;
+
+    cout << endl;
+
+    for(i = 1; i <= k; i++) {
+        if(i % 4 == 0) {
+            cout << " ";
+        }
+        if(a[i] > 9) {
+            if(a[i] == 10) {
+                cout << "A";
+            }
+            if(a[i] == 11) {
+                cout << "B";
+            }
+            if(a[i] == 12) {
+                cout << "C";
+            }
+            if(a[i] == 13) {
+                cout << "D";
+            }
+            if(a[i] == 14) {
+                cout << "E";
+            }
+            if(a[i] == 15) {
+                cout << "F";
+            }
+        } 
+        else {
+            cout << a[i];
+        }
+
+    }
+
+    cout << endl;
+
+    delete [] a;
+
+    system("pause");
+    return 0;
+}
\ No newline at end of file
diff --git a/cpp/system10-n/main.cpp b/cpp/system10-n/main.cpp
new file mode 100644
index 0000000..aa819d1
--- /dev/null
+++ b/cpp/system10-n/main.cpp
@@ -0,0 +1,128 @@
+#include <iostream>
+
+using namespace std;
+
+void hex() {
+    int i,k,n,m;
+
+    cout << "Podaj liczbe dziesietna: ";
+    cin >> n;
+    int *a = new int[n];
+    
+    m=n;
+
+    i = 1;
+    while(m>=1) {
+        a[i] = m % 16;
+        m = m / 16;
+        i++;
+    }
+
+    k = i - 1;
+
+    cout << endl;
+
+    for(i = 1; i <= k; i++) {
+        if(i % 4 == 0) {
+            cout << " ";
+        }
+        if(a[i] > 9) {
+            if(a[i] == 10) {
+                cout << "A";
+            }
+            if(a[i] == 11) {
+                cout << "B";
+            }
+            if(a[i] == 12) {
+                cout << "C";
+            }
+            if(a[i] == 13) {
+                cout << "D";
+            }
+            if(a[i] == 14) {
+                cout << "E";
+            }
+            if(a[i] == 15) {
+                cout << "F";
+            }
+        } 
+        else {
+            cout << a[i];
+        }
+
+    }
+
+    cout << endl;
+
+    delete [] a;
+}
+
+void octal() {
+        int i,k,n,m;
+
+    cout << "Podaj liczbe dziesietna: ";
+    cin >> n;
+    int *a = new int[n];
+    
+    m=n;
+
+    i = 1;
+    while(m>=1) {
+        a[i] = m % 8;
+        cout << a[i] << " ";
+        m = m / 8;
+        i++;
+    }
+
+    k = i - 1;
+
+    cout << endl << "K = " << k << endl;
+
+    for(i = 1; i <= k; i++) {
+        if(i % 3 == 0) {
+            cout << " " << a[i];
+        }
+        else {
+            cout << a[i];
+        }
+    }
+
+    cout << endl;
+
+    delete [] a;
+}
+
+int main() {
+    char choice;
+
+    cout << "Wybierz system :" << endl;
+    cout << "1. Binarny" << endl;
+    cout << "2. Oktalny" << endl;
+    cout << "3. Decymanalny" << endl;
+    cout << "4. Hexadecimalny" << endl;
+    cout << "Podaj swoj wybor: ";
+
+    cin >> choice;
+
+    switch(choice) {
+        case '1':
+            cout << "Wybierasz system binarny." << endl;
+            break;
+        case '2':
+            system("cls");
+            cout << "Wybierasz system oktalny." << endl;
+            octal(); 
+        case '3':
+            cout << "Wybierasz system dziesietny." << endl;
+            break;
+        case '4':
+            system("cls");
+            cout << "Wybierasz system szesnastkowy." << endl;
+            hex();
+        default:
+            break;
+    }
+
+    system("pause");
+    return 0;
+}
\ No newline at end of file