diff --git a/src/main/java/ru/ulstu/is/cbapp/Lab2/domain/Calculate.java b/src/main/java/ru/ulstu/is/cbapp/Lab2/domain/Calculate.java
index 7f1ce19..537e3f5 100644
--- a/src/main/java/ru/ulstu/is/cbapp/Lab2/domain/Calculate.java
+++ b/src/main/java/ru/ulstu/is/cbapp/Lab2/domain/Calculate.java
@@ -1,8 +1,8 @@
 package ru.ulstu.is.cbapp.Lab2.domain;
 
 public interface Calculate<T> {
-    Object add(T a, T b);
-    Object sut(T a, T b);
-    Object len(T a);
-    Object inv(T a);
+    T add(T a, T b);
+    T sut(T a, T b);
+    Integer len(T a);
+    T inv(T a);
 }
diff --git a/src/main/java/ru/ulstu/is/cbapp/Lab2/domain/StringCalculate.java b/src/main/java/ru/ulstu/is/cbapp/Lab2/domain/StringCalculate.java
index e482c09..02361f2 100644
--- a/src/main/java/ru/ulstu/is/cbapp/Lab2/domain/StringCalculate.java
+++ b/src/main/java/ru/ulstu/is/cbapp/Lab2/domain/StringCalculate.java
@@ -16,8 +16,8 @@ public class StringCalculate implements Calculate<String> {
     }
 
     @Override
-    public String len(String a) {
-        return "Длина = "+a.length();
+    public Integer len(String a) {
+        return a.length();
     }
 
     @Override
diff --git a/src/main/java/ru/ulstu/is/cbapp/Lab2/service/ServiceCalculate.java b/src/main/java/ru/ulstu/is/cbapp/Lab2/service/ServiceCalculate.java
index e69e95b..56d41dc 100644
--- a/src/main/java/ru/ulstu/is/cbapp/Lab2/service/ServiceCalculate.java
+++ b/src/main/java/ru/ulstu/is/cbapp/Lab2/service/ServiceCalculate.java
@@ -30,8 +30,8 @@ public class ServiceCalculate {
         catch (Exception ex){
             return new Errors(400, ex.getMessage());
         }
-
     }
+
     public Object sut(Object a, Object b, String type){
         Calculate calculate = (Calculate)applicationContext.getBean(type);
         if (a==null || a.equals("") || b==null || b.equals("")){
diff --git a/src/test/java/ru/ulstu/is/cbapp/CbappApplicationTests.java b/src/test/java/ru/ulstu/is/cbapp/CbappApplicationTests.java
index e7896d2..701a75a 100644
--- a/src/test/java/ru/ulstu/is/cbapp/CbappApplicationTests.java
+++ b/src/test/java/ru/ulstu/is/cbapp/CbappApplicationTests.java
@@ -1,13 +1,52 @@
 package ru.ulstu.is.cbapp;
 
+import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import ru.ulstu.is.cbapp.Lab2.service.ServiceCalculate;
 
 @SpringBootTest
 class CbappApplicationTests {
 
+	@Autowired
+	ServiceCalculate serviceCalculate;
+
 	@Test
-	void contextLoads() {
+	void stringSum() {
+		Assertions.assertEquals("testData",serviceCalculate.add("test","Data","string"));
+		Assertions.assertEquals("1022",serviceCalculate.add("102","2","string"));
+	}
+	@Test
+	void numberSum() {
+		Assertions.assertEquals(104,serviceCalculate.add("102","2","number"));
+	}
+	@Test
+	void stringSut() {
+		Assertions.assertEquals("tt",serviceCalculate.sut("test","es","string"));
+		Assertions.assertEquals("10",serviceCalculate.sut("102","2","string"));
+	}
+	@Test
+	void numberSut() {
+		Assertions.assertEquals(100,serviceCalculate.sut(102,2,"number"));
+	}
+	@Test
+	void stringLen() {
+		Assertions.assertEquals("Длина = 4",serviceCalculate.len("test","string"));
+	}
+	@Test
+	void numberLen() {
+		Assertions.assertEquals(3,serviceCalculate.len(305,"number"));
+		Assertions.assertEquals(2,serviceCalculate.len(24,"number"));
+	}
+	@Test
+	void stringInv() {
+		Assertions.assertEquals("gnirts",serviceCalculate.inv("string","string"));
+	}
+	@Test
+	void numberInv() {
+		Assertions.assertEquals(-102,serviceCalculate.inv(102,"number"));
+		Assertions.assertEquals(12,serviceCalculate.inv(-12,"number"));
 	}
 
 }