diff --git a/lesson_17/main.cpp b/lesson_17/main.cpp
new file mode 100644
index 0000000..4b9ba21
--- /dev/null
+++ b/lesson_17/main.cpp
@@ -0,0 +1,96 @@
+/*
+ * main.cpp
+ *
+ *  Created on: 8 авг. 2021 г.
+ *      Author: alexander
+ */
+#include <iostream>
+#include <iomanip>
+
+using namespace std;
+
+void floatType();
+void boolType();
+
+int main()
+{
+	// Размер типов данных
+	cout << "bool:\t\t" << sizeof(bool) << " bytes" << endl;
+	cout << "char:\t\t" << sizeof(char) << " bytes" << endl;
+	cout << "wchar_t:\t" << sizeof(wchar_t) << " bytes" << endl;
+	cout << "char16_t:\t" << sizeof(char16_t) << " bytes" << endl;
+	cout << "char32_t:\t" << sizeof(char32_t) << " bytes" << endl;
+	cout << "short:\t\t" << sizeof(short) << " bytes" << endl;
+	cout << "int:\t\t" << sizeof(int) << " bytes" << endl;
+	cout << "long:\t\t" << sizeof(long) << " bytes" << endl;
+	cout << "long long:\t" << sizeof(long long) << " bytes" << endl;
+	cout << "float:\t\t" << sizeof(float) << " bytes" << endl;
+	cout << "double:\t\t" << sizeof(double) << " bytes" << endl;
+	cout << "long double:\t" << sizeof(long double) << " bytes" << endl;
+
+	floatType();
+	boolType();
+
+	return 0;
+}
+
+void floatType()
+{
+
+
+	// Запись числа
+	int n(5);
+	double d(5.0);
+	float f(5.0f);
+
+	cout << "n:\t" << n << endl;
+	cout << "d:\t" << d << endl;
+	cout << "f:\t" << f << endl;
+
+	// Экспоненциальная запись чисел
+	{
+		double d1(5000.0);
+		double d2(5e3);
+		double d3(0.05);
+		double d4(5e-2);
+
+		cout << "d1:\t" << d1 << endl;   // 5000
+		cout << "d2:\t" << d2 << endl;   // 5000
+		cout << "d3:\t" << d3 << endl;   // 0.05
+		cout << "d4:\t" << d4 << endl;   // 0.05
+	}
+
+	// Тест
+	{
+		double d1(3.450e1);
+		double d2(4.000e-3);
+		double d3(1.23005e2);
+		double d4(1.46e5);
+		double d5(1.46000001e5);
+		double d6(8e-10);
+		double d7(3.45000e4);
+
+		cout << "d1:\t" << setprecision(4) << d1 << endl;   // 34.50
+		cout << "d2:\t" << setprecision(4) << d2 << endl;   // 0.004000
+		cout << "d3:\t" << setprecision(6) << d3 << endl;   // 123.005
+		cout << "d4:\t" << setprecision(3) << d4 << endl;   // 146000
+		cout << "d5:\t" << setprecision(9) << d5 << endl;   // 146000.001
+		cout << "d6:\t" << setprecision(1) << d6 << endl;   // 0.0000000008
+		cout << "d7:\t" << setprecision(6) << d7 << endl;   // 34500.0
+	}
+}
+
+void boolType()
+{
+	bool b1 = true;   // копирующая инициализация
+	bool b2(false);   // прямая инициализация
+	bool b3{true};    // uniform-инициализация (C++11)
+	bool b4 = false;  // операция присваивания
+
+	cout << b1 << endl;
+	cout << b2 << endl;
+	cout << b3 << endl;
+	cout << b4 << endl;
+}
+
+