diff --git a/android-app/src/main/java/org/solovyev/android/calculator/AndroidCalculator.java b/android-app/src/main/java/org/solovyev/android/calculator/AndroidCalculator.java
index 021f886b..adadb182 100644
--- a/android-app/src/main/java/org/solovyev/android/calculator/AndroidCalculator.java
+++ b/android-app/src/main/java/org/solovyev/android/calculator/AndroidCalculator.java
@@ -104,6 +104,11 @@ public class AndroidCalculator implements Calculator, CalculatorEventListener, S
 		return calculator.evaluate(operation, expression, sequenceId);
 	}
 
+	@Override
+	public boolean isCalculateOnFly() {
+		return calculator.isCalculateOnFly();
+	}
+
 	@Override
 	public boolean isConversionPossible(@Nonnull Generic generic, @Nonnull NumeralBase from, @Nonnull NumeralBase to) {
 		return calculator.isConversionPossible(generic, from, to);
diff --git a/core/src/main/java/org/solovyev/android/calculator/Calculator.java b/core/src/main/java/org/solovyev/android/calculator/Calculator.java
index 70167194..51bb6718 100644
--- a/core/src/main/java/org/solovyev/android/calculator/Calculator.java
+++ b/core/src/main/java/org/solovyev/android/calculator/Calculator.java
@@ -64,6 +64,8 @@ public interface Calculator extends CalculatorEventContainer, HistoryControl<Cal
 								 @Nonnull String expression,
 								 @Nonnull Long sequenceId);
 
+	boolean isCalculateOnFly();
+
 	/*
 	**********************************************************************
 	*
diff --git a/core/src/main/java/org/solovyev/android/calculator/CalculatorImpl.java b/core/src/main/java/org/solovyev/android/calculator/CalculatorImpl.java
index 87ab4ef5..69cab025 100644
--- a/core/src/main/java/org/solovyev/android/calculator/CalculatorImpl.java
+++ b/core/src/main/java/org/solovyev/android/calculator/CalculatorImpl.java
@@ -211,6 +211,11 @@ public class CalculatorImpl implements Calculator, CalculatorEventListener {
 		this.calculateOnFly = calculateOnFly;
 	}
 
+	@Override
+	public boolean isCalculateOnFly() {
+		return calculateOnFly;
+	}
+
 	@Nonnull
 	private CalculatorConversionEventData newConversionEventData(@Nonnull Long sequenceId,
 																 @Nonnull Generic value,
diff --git a/core/src/main/java/org/solovyev/android/calculator/CalculatorSpecialButton.java b/core/src/main/java/org/solovyev/android/calculator/CalculatorSpecialButton.java
index fc21c6c2..0d58ed09 100644
--- a/core/src/main/java/org/solovyev/android/calculator/CalculatorSpecialButton.java
+++ b/core/src/main/java/org/solovyev/android/calculator/CalculatorSpecialButton.java
@@ -102,6 +102,13 @@ public enum CalculatorSpecialButton {
 	equals("=") {
 		@Override
 		public void onClick(@Nonnull CalculatorKeyboard keyboard) {
+			final Calculator calculator = Locator.getInstance().getCalculator();
+			if (!calculator.isCalculateOnFly()) {
+				// no automatic calculations are => equals button must be used to calculate
+				calculator.evaluate();
+				return;
+			}
+
 			final CalculatorDisplayViewState displayViewState = Locator.getInstance().getDisplay().getViewState();
 			if (displayViewState.isValid()) {
 				final CharSequence text = displayViewState.getText();