diff --git a/src/main/java/org/solovyev/android/calculator/TextHighlighter.java b/src/main/java/org/solovyev/android/calculator/TextHighlighter.java
index 17044ba0..79e22d05 100644
--- a/src/main/java/org/solovyev/android/calculator/TextHighlighter.java
+++ b/src/main/java/org/solovyev/android/calculator/TextHighlighter.java
@@ -6,7 +6,6 @@
 
 package org.solovyev.android.calculator;
 
-import android.graphics.Color;
 import org.jetbrains.annotations.NotNull;
 import org.solovyev.android.calculator.math.MathType;
 import org.solovyev.android.calculator.model.ParseException;
@@ -26,9 +25,12 @@ public class TextHighlighter implements TextProcessor<String> {
 
 	public TextHighlighter(int baseColor) {
 		this.color = baseColor;
-		this.colorRed = Color.red(baseColor);
-		this.colorGreen = Color.green(baseColor);
-		this.colorBlue = Color.blue(baseColor);
+		//this.colorRed = Color.red(baseColor);
+		this.colorRed = (baseColor >> 16) & 0xFF;
+		//this.colorGreen = Color.green(baseColor);
+		this.colorGreen = (color >> 8) & 0xFF;
+		//this.colorBlue = Color.blue(baseColor);
+		this.colorBlue = color & 0xFF;
 	}
 
 	@NotNull
diff --git a/src/main/java/org/solovyev/android/calculator/math/Functions.java b/src/main/java/org/solovyev/android/calculator/math/Functions.java
index d2e616e4..db1890d0 100644
--- a/src/main/java/org/solovyev/android/calculator/math/Functions.java
+++ b/src/main/java/org/solovyev/android/calculator/math/Functions.java
@@ -49,8 +49,7 @@ public class Functions {
 		allPrefix = functions;
 	}
 
-	public final static String FACT = "!";
 	public final static String DEGREE = "°";
 
-	public static final List<String> allPostfix = Arrays.asList(FACT, DEGREE);
+	public static final List<String> allPostfix = Arrays.asList(DEGREE);
 }
diff --git a/src/main/java/org/solovyev/android/calculator/math/MathType.java b/src/main/java/org/solovyev/android/calculator/math/MathType.java
index 170343e8..d3832d6c 100644
--- a/src/main/java/org/solovyev/android/calculator/math/MathType.java
+++ b/src/main/java/org/solovyev/android/calculator/math/MathType.java
@@ -43,7 +43,20 @@ public enum MathType {
 		}
 	},
 
-	postfix_function(400, true, false, Functions.allPostfix),
+	postfix_function(400, true, false, Functions.allPostfix) {
+		@Override
+		protected String getSubstitute(@NotNull String match) {
+			final String result;
+
+			if (  match.equals(Functions.DEGREE)) {
+				result = PI + "/180";
+			} else {
+				result = null;
+			}
+
+			return result;
+		}
+	},
 	unary_operation(500, false, false, "-", "=", "!"),
 	binary_operation(600, false, false, "-", "+", "*", "×", "∙", "/", "^") {
 		@Override
diff --git a/src/main/java/org/solovyev/android/view/prefs/NumberPickerDialogPreference.java b/src/main/java/org/solovyev/android/view/prefs/NumberPickerDialogPreference.java
index cf848f03..f45706c8 100644
--- a/src/main/java/org/solovyev/android/view/prefs/NumberPickerDialogPreference.java
+++ b/src/main/java/org/solovyev/android/view/prefs/NumberPickerDialogPreference.java
@@ -14,7 +14,7 @@ import android.widget.LinearLayout;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.solovyev.android.view.widgets.NumberPicker;
-import org.solovyev.common.GenericIntervalMapper;
+import org.solovyev.common.NumberIntervalMapper;
 import org.solovyev.common.utils.Interval;
 import org.solovyev.common.utils.Mapper;
 
@@ -25,6 +25,8 @@ import org.solovyev.common.utils.Mapper;
  */
 public class NumberPickerDialogPreference extends AbstractDialogPreference<Integer> implements NumberPicker.OnChangedListener {
 
+	private static final NumberIntervalMapper<Integer> INTEGER_NUMBER_INTERVAL_MAPPER = new NumberIntervalMapper<Integer>(Integer.class);
+
 	@NotNull
 	private NumberPicker numberPicker;
 
@@ -35,7 +37,7 @@ public class NumberPickerDialogPreference extends AbstractDialogPreference<Integ
 		super(context, attrs, null, false);
 
 		//noinspection ConstantConditions
-		boundaries = new GenericIntervalMapper<Integer>(getMapper()).parseValue(attrs.getAttributeValue(localNameSpace, "boundaries"));
+		boundaries = INTEGER_NUMBER_INTERVAL_MAPPER.parseValue(attrs.getAttributeValue(localNameSpace, "boundaries"));
 
 		createPreferenceView();
 	}
@@ -75,17 +77,7 @@ public class NumberPickerDialogPreference extends AbstractDialogPreference<Integ
 	@NotNull
 	@Override
 	protected Mapper<Integer> getMapper() {
-		return new Mapper<Integer>() {
-			@Override
-			public String formatValue(@Nullable Integer value) throws IllegalArgumentException {
-				return String.valueOf(value);
-			}
-
-			@Override
-			public Integer parseValue(@Nullable String value) throws IllegalArgumentException {
-				return Integer.valueOf(value);
-			}
-		};
+		return INTEGER_NUMBER_INTERVAL_MAPPER.getMapper();
 	}
 
 	@Override
diff --git a/src/main/java/org/solovyev/common/AbstractIntervalMapper.java b/src/main/java/org/solovyev/common/AbstractIntervalMapper.java
index de6b880b..2b90eb50 100644
--- a/src/main/java/org/solovyev/common/AbstractIntervalMapper.java
+++ b/src/main/java/org/solovyev/common/AbstractIntervalMapper.java
@@ -6,7 +6,6 @@
 
 package org.solovyev.common;
 
-import android.util.Log;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.solovyev.common.utils.*;
@@ -35,13 +34,16 @@ public abstract class AbstractIntervalMapper<T> implements Mapper<Interval<T>> {
 
 	@Override
 	public Interval<T> parseValue(@Nullable String s) throws IllegalArgumentException {
-		Log.d(AbstractIntervalMapper.class.getName(), "Parsing: " + s);
+		//Log.d(AbstractIntervalMapper.class.getName(), "Parsing: " + s);
 		final List<T> list = CollectionsUtils.split(s, ";", getParser());
 
 		assert list.size() == 2;
-		return new IntervalImpl<T>(list.get(0), list.get(1));
+		return newInstance(list.get(0), list.get(1));
 	}
 
+	@NotNull
+	protected abstract Interval<T> newInstance(@Nullable T left, @Nullable T right);
+
 	@NotNull
 	protected abstract Parser<T> getParser();
 }
diff --git a/src/main/java/org/solovyev/common/GenericIntervalMapper.java b/src/main/java/org/solovyev/common/GenericIntervalMapper.java
index f2a6414b..e6468f47 100644
--- a/src/main/java/org/solovyev/common/GenericIntervalMapper.java
+++ b/src/main/java/org/solovyev/common/GenericIntervalMapper.java
@@ -16,7 +16,7 @@ import org.solovyev.common.utils.Parser;
  * Date: 9/26/11
  * Time: 10:45 PM
  */
-public class GenericIntervalMapper<T> extends AbstractIntervalMapper<T> {
+public abstract class GenericIntervalMapper<T> extends AbstractIntervalMapper<T> {
 
 	@NotNull
 	private final Mapper<T> mapper;
@@ -36,4 +36,9 @@ public class GenericIntervalMapper<T> extends AbstractIntervalMapper<T> {
 	protected Parser<T> getParser() {
 		return mapper;
 	}
+
+	@NotNull
+	public Mapper<T> getMapper() {
+		return mapper;
+	}
 }
diff --git a/src/main/java/org/solovyev/common/NumberIntervalMapper.java b/src/main/java/org/solovyev/common/NumberIntervalMapper.java
index 2f55d1e0..3e09cf95 100644
--- a/src/main/java/org/solovyev/common/NumberIntervalMapper.java
+++ b/src/main/java/org/solovyev/common/NumberIntervalMapper.java
@@ -7,6 +7,9 @@
 package org.solovyev.common;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.solovyev.common.utils.Interval;
+import org.solovyev.common.utils.NumberInterval;
 
 /**
 * User: serso
@@ -18,4 +21,10 @@ public class NumberIntervalMapper<T extends Number> extends GenericIntervalMappe
 	public NumberIntervalMapper(@NotNull Class<T> clazz) {
 		super(new NumberMapper<T>(clazz));
 	}
+
+	@NotNull
+	@Override
+	protected Interval<T> newInstance(@Nullable T left, @Nullable T right) {
+		return new NumberInterval<T>(left, right);
+	}
 }
diff --git a/src/test/java/org/solovyev/android/calculator/jscl/FromJsclNumericTextProcessorTest.java b/src/test/java/org/solovyev/android/calculator/jscl/FromJsclNumericTextProcessorTest.java
index 1ad6633a..61840a50 100644
--- a/src/test/java/org/solovyev/android/calculator/jscl/FromJsclNumericTextProcessorTest.java
+++ b/src/test/java/org/solovyev/android/calculator/jscl/FromJsclNumericTextProcessorTest.java
@@ -20,7 +20,7 @@ public class FromJsclNumericTextProcessorTest {
 	public void testCreateResultForComplexNumber() throws Exception {
 		final FromJsclNumericTextProcessor cm = new FromJsclNumericTextProcessor();
 
-		Assert.assertEquals("1.22133+23123.0i", cm.createResultForComplexNumber("1.22133232+23123*i"));
+		Assert.assertEquals("1.22133+23 123i", cm.createResultForComplexNumber("1.22133232+23123*i"));
 		Assert.assertEquals("1.22133+1.2i", cm.createResultForComplexNumber("1.22133232+1.2*i"));
 		Assert.assertEquals("1.22i", cm.createResultForComplexNumber("1.22*i"));
 		Assert.assertEquals("i", cm.createResultForComplexNumber("i"));
diff --git a/src/test/java/org/solovyev/android/calculator/model/CalculatorEngineTest.java b/src/test/java/org/solovyev/android/calculator/model/CalculatorEngineTest.java
index 0f533914..621f81fa 100644
--- a/src/test/java/org/solovyev/android/calculator/model/CalculatorEngineTest.java
+++ b/src/test/java/org/solovyev/android/calculator/model/CalculatorEngineTest.java
@@ -38,7 +38,7 @@ public class CalculatorEngineTest {
 		} catch (EvalError evalError) {
 			Assert.fail();
 		} catch (ParseException e) {
-			if ( e.getMessage().startsWith("Too long calculation") ) {
+			if (e.getMessage().startsWith("Too long calculation")) {
 
 			} else {
 				Assert.fail();
@@ -52,7 +52,7 @@ public class CalculatorEngineTest {
 		} catch (EvalError evalError) {
 			Assert.fail();
 		} catch (ParseException e) {
-			if ( e.getMessage().startsWith("Too long calculation") ) {
+			if (e.getMessage().startsWith("Too long calculation")) {
 				final long end = System.currentTimeMillis();
 				Assert.assertTrue(end - start < 1000);
 			} else {
@@ -102,7 +102,7 @@ public class CalculatorEngineTest {
 		CalculatorEngine.instance.getVarsRegister().addVar(null, new Var.Builder("k1", 4d));
 		Assert.assertEquals("4", cm.evaluate(JsclOperation.numeric, "k11"));
 
-		CalculatorEngine.instance.getVarsRegister().addVar(null, new Var.Builder("t", (String)null));
+		CalculatorEngine.instance.getVarsRegister().addVar(null, new Var.Builder("t", (String) null));
 		Assert.assertEquals("11t", cm.evaluate(JsclOperation.numeric, "t11"));
 		Assert.assertEquals("11et", cm.evaluate(JsclOperation.numeric, "t11e"));
 		Assert.assertEquals("11×Infinityt", cm.evaluate(JsclOperation.numeric, "t11∞"));
@@ -115,13 +115,13 @@ public class CalculatorEngineTest {
 		try {
 			cm.evaluate(JsclOperation.numeric, "cos(cos(cos(cos(acos(acos(acos(acos(acos(acos(acos(acos(cos(cos(cos(cos(cosh(acos(cos(cos(cos(cos(cos(acos(acos(acos(acos(acos(acos(acos(acos(cos(cos(cos(cos(cosh(acos(cos())))))))))))))))))))))))))))))))))))))");
 			Assert.fail();
-		} catch (ParseException e){
+		} catch (ParseException e) {
 		}
 		Assert.assertEquals("NaN", cm.evaluate(JsclOperation.numeric, "ln(ln(ln(ln(ln(ln(ln(ln(ln(ln(ln(ln(ln(ln(ln(100)))))))))))))))"));
 		try {
 			cm.evaluate(JsclOperation.numeric, "cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos())))))))))))))))))))))))))))))))))))");
 			Assert.fail();
-		} catch (ParseException e){
+		} catch (ParseException e) {
 		}
 		Assert.assertEquals("0.739", cm.evaluate(JsclOperation.numeric, "cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(cos(1))))))))))))))))))))))))))))))))))))"));
 
@@ -151,4 +151,17 @@ public class CalculatorEngineTest {
 
 
 	}
+
+	@Test
+	public void testDegrees() throws Exception {
+		final CalculatorEngine cm = CalculatorEngine.instance;
+
+		cm.setPrecision(3);
+		Assert.assertEquals("0.017", cm.evaluate(JsclOperation.numeric, "°"));
+		Assert.assertEquals("0.017", cm.evaluate(JsclOperation.numeric, "1°"));
+		Assert.assertEquals("0.349", cm.evaluate(JsclOperation.numeric, "20.0°"));
+		Assert.assertEquals("0.5", cm.evaluate(JsclOperation.numeric, "sin(30°)"));
+		Assert.assertEquals("0.524", cm.evaluate(JsclOperation.numeric, "asin(sin(30°))"));
+
+	}
 }
diff --git a/src/test/java/org/solovyev/android/calculator/model/FromJsclSimplifyTextProcessorTest.java b/src/test/java/org/solovyev/android/calculator/model/FromJsclSimplifyTextProcessorTest.java
index bab1b6c7..e534d41d 100644
--- a/src/test/java/org/solovyev/android/calculator/model/FromJsclSimplifyTextProcessorTest.java
+++ b/src/test/java/org/solovyev/android/calculator/model/FromJsclSimplifyTextProcessorTest.java
@@ -4,6 +4,8 @@ import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
+import java.text.DecimalFormatSymbols;
+
 /**
  * User: serso
  * Date: 10/20/11
@@ -20,6 +22,9 @@ public class FromJsclSimplifyTextProcessorTest {
 	public void testProcess() throws Exception {
 		FromJsclSimplifyTextProcessor tp = new FromJsclSimplifyTextProcessor();
 		Assert.assertEquals("(e)", tp.process("(2.718281828459045)"));
+		DecimalFormatSymbols decimalGroupSymbols = new DecimalFormatSymbols();
+		decimalGroupSymbols.setGroupingSeparator(' ');
+		CalculatorEngine.instance.setDecimalGroupSymbols(decimalGroupSymbols);
 		Assert.assertEquals("123 456 789e", tp.process("123456789*2.718281828459045"));
 		Assert.assertEquals("123 456 789e", tp.process("123 456 789 * 2.718281828459045"));
 		Assert.assertEquals("t11e", tp.process("t11*2.718281828459045"));
diff --git a/src/test/java/org/solovyev/android/calculator/model/ToJsclTextProcessorTest.java b/src/test/java/org/solovyev/android/calculator/model/ToJsclTextProcessorTest.java
index d564b110..74690c8d 100644
--- a/src/test/java/org/solovyev/android/calculator/model/ToJsclTextProcessorTest.java
+++ b/src/test/java/org/solovyev/android/calculator/model/ToJsclTextProcessorTest.java
@@ -107,4 +107,17 @@ public class ToJsclTextProcessorTest {
 		Assert.assertEquals(2, preprocessor.getPostfixFunctionStart("2+sin(5sin(5sin(5)))!", 19));
 		Assert.assertEquals(5, preprocessor.getPostfixFunctionStart("2.23+sin(5.4434234*sin(5.1+1))!", 29));
 	}
+
+	@Test
+	public void testDegrees() throws Exception {
+		final ToJsclTextProcessor preprocessor = new ToJsclTextProcessor();
+
+		Assert.assertEquals( "", preprocessor.process("").toString());
+		Assert.assertEquals( "3.141592653589793/180", preprocessor.process("°").toString());
+		Assert.assertEquals( "1*3.141592653589793/180", preprocessor.process("1°").toString());
+		Assert.assertEquals( "20.0*3.141592653589793/180", preprocessor.process("20.0°").toString());
+		Assert.assertEquals( "sin(30*3.141592653589793/180)", preprocessor.process("sin(30°)").toString());
+		Assert.assertEquals( "asin(sin(3.141592653589793/6))*3.141592653589793/180", preprocessor.process("asin(sin(π/6))°").toString());
+
+	}
 }
diff --git a/src/test/java/org/solovyev/common/FloatIntervalMapperTest.java b/src/test/java/org/solovyev/common/FloatIntervalMapperTest.java
index 5c93cc98..2fc0f46c 100644
--- a/src/test/java/org/solovyev/common/FloatIntervalMapperTest.java
+++ b/src/test/java/org/solovyev/common/FloatIntervalMapperTest.java
@@ -3,8 +3,8 @@ package org.solovyev.common;
 import junit.framework.Assert;
 import org.junit.Test;
 import org.solovyev.common.utils.Interval;
-import org.solovyev.common.utils.IntervalImpl;
 import org.solovyev.common.utils.Mapper;
+import org.solovyev.common.utils.NumberInterval;
 
 /**
  * User: serso
@@ -17,7 +17,7 @@ public class FloatIntervalMapperTest {
 	public void testParse() throws Exception {
 		final Mapper<Interval<Float>> mapper = new NumberIntervalMapper<Float>(Float.class);
 
-		Assert.assertEquals(new IntervalImpl<Float>(1.2f, 12.2f), mapper.parseValue("1.2;12.2"));
-		Assert.assertEquals(new IntervalImpl<Float>(0f, 0f), mapper.parseValue("0;0"));
+		Assert.assertEquals(new NumberInterval<Float>(1.2f, 12.2f), mapper.parseValue("1.2;12.2"));
+		Assert.assertEquals(new NumberInterval<Float>(0f, 0f), mapper.parseValue("0;0"));
 	}
 }
diff --git a/src/test/java/org/solovyev/common/math/DiscreteNormalizerTest.java b/src/test/java/org/solovyev/common/math/DiscreteNormalizerTest.java
index ce4c5906..ef2fc2d0 100644
--- a/src/test/java/org/solovyev/common/math/DiscreteNormalizerTest.java
+++ b/src/test/java/org/solovyev/common/math/DiscreteNormalizerTest.java
@@ -13,7 +13,7 @@ public class DiscreteNormalizerTest {
 
 	@Test
 	public void testNormalize() throws Exception {
-	 	DiscreteNormalizer dn = new DiscreteNormalizer(0, 10, 1);
+	 	DiscreteNormalizer dn = new DiscreteNormalizer(0, 10, 1d);
 
 		Assert.assertTrue(MathUtils.equals(0, dn.normalize(0.5), 2));
 		Assert.assertTrue(MathUtils.equals(0, dn.normalize(0.99), 2));
@@ -25,7 +25,7 @@ public class DiscreteNormalizerTest {
 
 	@Test
 	public void testDenormalize() throws Exception {
-		DiscreteNormalizer dn = new DiscreteNormalizer(0, 10, 1);
+		DiscreteNormalizer dn = new DiscreteNormalizer(0, 10, 1d);
 
 		Assert.assertTrue(MathUtils.equals(0, dn.normalize(dn.denormalize(0)), 2));
 		Assert.assertTrue(MathUtils.equals(0.1, dn.normalize(dn.denormalize(0.1)), 2));