diff --git a/res/values-ru/strings.xml b/res/values-ru/strings.xml
index 466f8170..40c917f0 100644
--- a/res/values-ru/strings.xml
+++ b/res/values-ru/strings.xml
@@ -35,6 +35,8 @@
 	<string name="c_vars">переменные</string>
 
 	<string name="c_calc_color_display_title">Подсветка выражений</string>
+	<string name="c_calc_round_result_title">Округление результата</string>
+	<string name="c_calc_round_result_summary">Включает/выключает округление результата</string>
 	<string name="p_calc_result_precision_title">Точность результата</string>
 	<string name="c_exit">Выход</string>
 	<string name="c_add">Добавить</string>
diff --git a/res/values/default_values.xml b/res/values/default_values.xml
index 0e269f30..eea88c45 100644
--- a/res/values/default_values.xml
+++ b/res/values/default_values.xml
@@ -22,6 +22,9 @@
 	<string name="p_calc_haptic_feedback_key">org.solovyev.android.calculator.CalculatorModel_haptic_feedback</string>
 	<string name="p_calc_haptic_feedback">false</string>
 
+	<string name="p_calc_round_result_key">org.solovyev.android.calculator.CalculatorModel_round_result</string>
+	<string name="p_calc_round_result">true</string>
+
 	<string name="p_calc_vars">org.solovyev.android.calculator.CalculatorModel_vars</string>
 
 	<string name="p_calc_theme_key">org.solovyev.android.calculator.CalculatorActivity_calc_theme</string>
diff --git a/res/values/strings.xml b/res/values/strings.xml
index e1a4fd65..fdc72cf2 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -38,6 +38,8 @@
 	<string name="c_vars">vars</string>
 
 	<string name="c_calc_color_display_title">Highlight expressions</string>
+	<string name="c_calc_round_result_title">Round result</string>
+	<string name="c_calc_round_result_summary">Toggles rounding of the result</string>
 	<string name="p_calc_result_precision_title">Precision of result</string>
 	<string name="c_exit">Exit</string>
 	<string name="c_add">Add</string>
diff --git a/res/xml/main_preferences.xml b/res/xml/main_preferences.xml
index e29b6125..e8cce53f 100644
--- a/res/xml/main_preferences.xml
+++ b/res/xml/main_preferences.xml
@@ -4,12 +4,18 @@
 				  xmlns:range="http://schemas.android.com/apk/res/org.solovyev.android.calculator">
 	<PreferenceCategory a:title="@string/c_prefs_calculations_category">
 
+		<android.preference.CheckBoxPreference
+				a:key="@string/p_calc_round_result_key"
+				a:summary="@string/c_calc_round_result_summary"
+				a:title="@string/c_calc_round_result_title"
+				a:defaultValue="true"/>
+
 		<org.solovyev.android.view.prefs.NumberPickerDialogPreference
 				a:key="@string/p_calc_result_precision_key"
 				a:title="@string/p_calc_result_precision_title"
 				a:summary="@string/c_calc_result_precision_summary"
 				a:defaultValue="5"
-				range:boundaries="0;10"/>
+				range:boundaries="0;16"/>
 
 		<ListPreference a:key="@string/p_calc_grouping_separator_key"
 						a:title="@string/c_calc_grouping_separator"
diff --git a/src/main/java/org/solovyev/android/calculator/CalculatorActivity.java b/src/main/java/org/solovyev/android/calculator/CalculatorActivity.java
index d0defba6..5483a155 100644
--- a/src/main/java/org/solovyev/android/calculator/CalculatorActivity.java
+++ b/src/main/java/org/solovyev/android/calculator/CalculatorActivity.java
@@ -481,10 +481,15 @@ public class CalculatorActivity extends Activity implements FontSizeAdjuster, Sh
 	}
 
 	@Override
-	public void onSharedPreferenceChanged(SharedPreferences preferences, @Nullable String s) {
+	public void onSharedPreferenceChanged(SharedPreferences preferences, @Nullable String key) {
 		dpclRegister.announce().onDragPreferencesChange(SimpleOnDragListener.getPreferences(preferences, this));
 
-		CalculatorEngine.instance.reset(this, preferences);
+		if (CalculatorEngine.GROUPING_SEPARATOR_P_KEY.equals(key) ||
+				CalculatorEngine.ROUND_RESULT_P_KEY.equals(key) ||
+					CalculatorEngine.RESULT_PRECISION_P_KEY.equals(key)) {
+			CalculatorEngine.instance.reset(this, preferences);
+			this.calculatorModel.evaluate();
+		}
 
 		final Boolean colorExpressionsInBracketsDefault = new BooleanMapper().parseValue(this.getString(R.string.p_calc_color_display));
 		assert colorExpressionsInBracketsDefault != null;
diff --git a/src/main/java/org/solovyev/android/calculator/CalculatorPreferencesActivity.java b/src/main/java/org/solovyev/android/calculator/CalculatorPreferencesActivity.java
index 02057ba0..314f6808 100644
--- a/src/main/java/org/solovyev/android/calculator/CalculatorPreferencesActivity.java
+++ b/src/main/java/org/solovyev/android/calculator/CalculatorPreferencesActivity.java
@@ -5,20 +5,33 @@
 
 package org.solovyev.android.calculator;
 
+import android.content.SharedPreferences;
 import android.os.Bundle;
 import android.preference.PreferenceActivity;
+import org.solovyev.android.calculator.model.CalculatorEngine;
 
 /**
  * User: serso
  * Date: 7/16/11
  * Time: 6:37 PM
  */
-public class CalculatorPreferencesActivity extends PreferenceActivity {
+public class CalculatorPreferencesActivity extends PreferenceActivity implements SharedPreferences.OnSharedPreferenceChangeListener {
 
 	@Override
 	protected void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 
 		addPreferencesFromResource(R.xml.main_preferences);
+
+		final SharedPreferences preferences = getPreferenceManager().getSharedPreferences();
+		preferences.registerOnSharedPreferenceChangeListener(this);
+		onSharedPreferenceChanged(preferences, CalculatorEngine.ROUND_RESULT_P_KEY);
+	}
+
+	@Override
+	public void onSharedPreferenceChanged(SharedPreferences preferences, String key) {
+		if (CalculatorEngine.ROUND_RESULT_P_KEY.equals(key)) {
+			findPreference(CalculatorEngine.RESULT_PRECISION_P_KEY).setEnabled(preferences.getBoolean(key, true));
+		}
 	}
 }
diff --git a/src/main/java/org/solovyev/android/calculator/model/CalculatorEngine.java b/src/main/java/org/solovyev/android/calculator/model/CalculatorEngine.java
index 3764e8e3..abedd595 100644
--- a/src/main/java/org/solovyev/android/calculator/model/CalculatorEngine.java
+++ b/src/main/java/org/solovyev/android/calculator/model/CalculatorEngine.java
@@ -44,8 +44,11 @@ public enum CalculatorEngine {
 	public static final String GROUPING_SEPARATOR_P_KEY = "org.solovyev.android.calculator.CalculatorActivity_calc_grouping_separator";
 	private static final String GROUPING_SEPARATOR_DEFAULT = " ";
 
-	private static final String RESULT_PRECISION_P_KEY = "org.solovyev.android.calculator.CalculatorModel_result_precision";
-	private static final String RESULT_PRECISION_DEFAULT = "5";
+	public static final String ROUND_RESULT_P_KEY = "org.solovyev.android.calculator.CalculatorModel_round_result";
+	public static final boolean ROUND_RESULT_DEFAULT = true;
+
+	public static final String RESULT_PRECISION_P_KEY = "org.solovyev.android.calculator.CalculatorModel_result_precision";
+	public static final String RESULT_PRECISION_DEFAULT = "5";
 
 	@NotNull
 	private Interpreter interpreter;
@@ -53,6 +56,8 @@ public enum CalculatorEngine {
 	@NotNull
 	private final Object lock = new Object();
 
+	private boolean roundResult = true;
+
 	private int precision = 5;
 
 	@NotNull
@@ -87,9 +92,13 @@ public enum CalculatorEngine {
 			final DecimalFormat df = new DecimalFormat();
 			df.setDecimalFormatSymbols(decimalGroupSymbols);
 			df.setGroupingUsed(useGroupingSeparator);
-			if (round) {
-				df.setMaximumFractionDigits(instance.getPrecision());
-				return df.format(new BigDecimal(value).setScale(instance.getPrecision(), BigDecimal.ROUND_HALF_UP).doubleValue());
+			if (round ) {
+				if (isRoundResult()) {
+					df.setMaximumFractionDigits(instance.getPrecision());
+					return df.format(new BigDecimal(value).setScale(instance.getPrecision(), BigDecimal.ROUND_HALF_UP).doubleValue());
+				} else {
+					return String.valueOf(value);
+				}
 			} else {
 				return df.format(value);
 			}
@@ -217,7 +226,7 @@ public enum CalculatorEngine {
 		}
 	}
 
-	public int getPrecision() {
+	private int getPrecision() {
 		return precision;
 	}
 
@@ -225,6 +234,14 @@ public enum CalculatorEngine {
 		this.precision = precision;
 	}
 
+	private boolean isRoundResult() {
+		return roundResult;
+	}
+
+	public void setRoundResult(boolean roundResult) {
+		this.roundResult = roundResult;
+	}
+
 	public void init(@Nullable Context context, @Nullable SharedPreferences preferences) throws EvalError {
 		synchronized (lock) {
 			reset(context, preferences);
@@ -238,6 +255,7 @@ public enum CalculatorEngine {
 				final NumberMapper<Integer> integerNumberMapper = new NumberMapper<Integer>(Integer.class);
 				//noinspection ConstantConditions
 				this.setPrecision(integerNumberMapper.parseValue(preferences.getString(RESULT_PRECISION_P_KEY, RESULT_PRECISION_DEFAULT)));
+				this.setRoundResult(preferences.getBoolean(ROUND_RESULT_P_KEY, ROUND_RESULT_DEFAULT));
 
 				final String groupingSeparator = preferences.getString(GROUPING_SEPARATOR_P_KEY, GROUPING_SEPARATOR_DEFAULT);
 				if (StringUtils.isEmpty(groupingSeparator)) {