diff --git a/tdd_intro/homework/03_bank_ocr/test.cpp b/tdd_intro/homework/03_bank_ocr/test.cpp
index a01540b..cf5a572 100644
--- a/tdd_intro/homework/03_bank_ocr/test.cpp
+++ b/tdd_intro/homework/03_bank_ocr/test.cpp
@@ -86,6 +86,7 @@ Example input and output
 */
 #include <gtest/gtest.h>
 #include <string>
+#include <cmath>
 
 const unsigned short g_digitLen = 3;
 const unsigned short g_linesInDigit = 3;
@@ -140,6 +141,18 @@ const Digit s_digit9 = { " _ ",
                          "|_|",
                          " _|"
                        };
+const Digit s_incorrectDigit1 = { "   ",
+                                  "|_|",
+                                  " _|"
+                                };
+const Digit s_incorrectDigit2 = { "   ",
+                                  "| |",
+                                  "|_|"
+                                };
+const Digit s_incorrectDigit3 = { " _ ",
+                                  "|_|",
+                                  "| |"
+                                };
 
 const Display s_displayAll0 = { " _  _  _  _  _  _  _  _  _ ",
                                 "| || || || || || || || || |",
@@ -195,3 +208,205 @@ const Display s_display123456789 = { "    _  _     _  _  _  _  _ ",
                                      "  | _| _||_||_ |_   ||_||_|",
                                      "  ||_  _|  | _||_|  ||_| _|"
 };
+
+const Display s_display234432234 = { " _  _        _  _  _  _    ",
+                                     " _| _||_||_| _| _| _| _||_|",
+                                     "|_  _|  |  | _||_ |_  _|  |"
+};
+
+/*
+ *test list
+ *1) check strings with single digit 0
+ *2) check strings with single digit 1
+ *...
+ *10) check strings with single digit 9
+ *11) check incorrect symbol
+ *11) check 9 similar symbols
+ *12) check 9 random symbols
+ *13) acceptance test
+ */
+
+int ConvertDigit(const Digit &digit)
+{
+    std::string high = digit.lines[0];
+    std::string mid = digit.lines[1];
+    std::string low = digit.lines[2];
+
+    int mask = high.at(1) == '_' ? 1 : 0;
+    mask += mid.at(0) == '|' ? 2 : 0;
+    mask += mid.at(1) == '_' ? 4 : 0;
+    mask += mid.at(2) == '|' ? 8 : 0;
+    mask += low.at(0) == '|' ? 16 : 0;
+    mask += low.at(1) == '_' ? 32 : 0;
+
+    // 1 - 001000 - 8
+    // 2 - 111101 - 61
+    // 3 - 101101 - 45
+    // 4 - 001110 - 14
+    // 5 - 100111 - 39
+    // 6 - 110111 - 55
+    // 7 - 001001 - 9
+    // 8 - 111111 - 63
+    // 9 - 101111 - 47
+    // 0 - 111011 - 59
+
+    switch(mask)
+    {
+    case 8:
+        return 1;
+    case 61:
+        return 2;
+    case 45:
+        return 3;
+    case 14:
+        return 4;
+    case 39:
+        return 5;
+    case 55:
+        return 6;
+    case 9:
+        return 7;
+    case 63:
+        return 8;
+    case 47:
+        return 9;
+    case 59:
+        return 0;
+
+    default:
+        throw std::runtime_error("Unknown symbol found");
+    }
+}
+
+int ConvertNumber(const Display &number)
+{
+    int result = 0;
+    for(int i = 0; i < g_digitsOnDisplay; ++i)
+    {
+        int position = i * g_digitLen;
+        int multiplier = std::pow(10, g_digitsOnDisplay - i - 1);
+        result += multiplier * ConvertDigit({std::string(number.lines[0].c_str() + position),
+                                             std::string(number.lines[1].c_str() + position),
+                                             std::string(number.lines[2].c_str() + position)});
+    }
+    return result;
+}
+
+
+TEST(BankOCR, CheckDigitZero)
+{
+    ASSERT_EQ(0, ConvertDigit(s_digit0));
+}
+
+TEST(BankOCR, CheckDigitOne)
+{
+    ASSERT_EQ(1, ConvertDigit(s_digit1));
+}
+
+TEST(BankOCR, CheckDigitTwo)
+{
+    ASSERT_EQ(2, ConvertDigit(s_digit2));
+}
+
+TEST(BankOCR, CheckDigitThree)
+{
+    ASSERT_EQ(3, ConvertDigit(s_digit3));
+}
+
+TEST(BankOCR, CheckDigitFour)
+{
+    ASSERT_EQ(4, ConvertDigit(s_digit4));
+}
+
+TEST(BankOCR, CheckDigitFive)
+{
+    ASSERT_EQ(5, ConvertDigit(s_digit5));
+}
+
+TEST(BankOCR, CheckDigitSix)
+{
+    ASSERT_EQ(6, ConvertDigit(s_digit6));
+}
+
+TEST(BankOCR, CheckDigitSeven)
+{
+    ASSERT_EQ(7, ConvertDigit(s_digit7));
+}
+
+TEST(BankOCR, CheckDigitEight)
+{
+    ASSERT_EQ(8, ConvertDigit(s_digit8));
+}
+
+TEST(BankOCR, CheckDigitNine)
+{
+    ASSERT_EQ(9, ConvertDigit(s_digit9));
+}
+
+TEST(BankOCR, CheckIncorectDigits)
+{
+    EXPECT_THROW(ConvertDigit(s_incorrectDigit1), std::runtime_error);
+    EXPECT_THROW(ConvertDigit(s_incorrectDigit2), std::runtime_error);
+    EXPECT_THROW(ConvertDigit(s_incorrectDigit3), std::runtime_error);
+}
+
+
+TEST(BankOCR, CheckNumberAll0)
+{
+    ASSERT_EQ(000000000, ConvertNumber(s_displayAll0));
+}
+
+TEST(BankOCR, CheckNumberAll1)
+{
+    ASSERT_EQ(111111111, ConvertNumber(s_displayAll1));
+}
+
+TEST(BankOCR, CheckNumberAll2)
+{
+    ASSERT_EQ(222222222, ConvertNumber(s_displayAll2));
+}
+
+TEST(BankOCR, CheckNumberAll3)
+{
+    ASSERT_EQ(333333333, ConvertNumber(s_displayAll3));
+}
+
+TEST(BankOCR, CheckNumberAll4)
+{
+    ASSERT_EQ(444444444, ConvertNumber(s_displayAll4));
+}
+
+TEST(BankOCR, CheckNumberAll5)
+{
+    ASSERT_EQ(555555555, ConvertNumber(s_displayAll5));
+}
+
+TEST(BankOCR, CheckNumberAll6)
+{
+    ASSERT_EQ(666666666, ConvertNumber(s_displayAll6));
+}
+
+TEST(BankOCR, CheckNumberAll7)
+{
+    ASSERT_EQ(777777777, ConvertNumber(s_displayAll7));
+}
+
+TEST(BankOCR, CheckNumberAll8)
+{
+    ASSERT_EQ(888888888, ConvertNumber(s_displayAll8));
+}
+
+TEST(BankOCR, CheckNumberAll9)
+{
+    ASSERT_EQ(999999999, ConvertNumber(s_displayAll9));
+}
+
+TEST(BankOCR, CheckNumberAll123456789)
+{
+    ASSERT_EQ(123456789, ConvertNumber(s_display123456789));
+}
+
+TEST(BankOCR, Acceptance)
+{
+    ASSERT_EQ(234432234, ConvertNumber(s_display234432234));
+}