diff --git a/kcalc.cpp b/kcalc.cpp
--- a/kcalc.cpp
+++ b/kcalc.cpp
@@ -922,7 +922,8 @@
 //------------------------------------------------------------------------------
 void KCalculator::slotNumberclicked(int number_clicked) {
 
-    calc_display->enterDigit(number_clicked);
+	calc_display->enterDigit(number_clicked);
+	core.setOnlyUpdateOperation(false);
 }
 
 //------------------------------------------------------------------------------
@@ -2055,6 +2056,7 @@
 
 	if(flags & UPDATE_FROM_CORE) {
 		calc_display->updateFromCore(core, (flags & UPDATE_STORE_RESULT) != 0);
+		core.setOnlyUpdateOperation(true);
 	} else {
 		calc_display->update();
 	}
diff --git a/kcalc_core.h b/kcalc_core.h
--- a/kcalc_core.h
+++ b/kcalc_core.h
@@ -106,6 +106,8 @@
     void TangensHyp(const KNumber &input);
 
     void Reset();
+    void setOnlyUpdateOperation(bool update);
+    bool getOnlyUpdateOperation() const;
 
 private:
     KStats stats;
@@ -141,6 +143,7 @@
     Operation last_operation_;
     KNumber last_repeat_number_;
     bool repeat_mode_;
+    bool only_update_operation_;
 
     bool percent_mode_;
 
diff --git a/kcalc_core.cpp b/kcalc_core.cpp
--- a/kcalc_core.cpp
+++ b/kcalc_core.cpp
@@ -169,8 +169,8 @@
 
 }
 
-
-CalcEngine::CalcEngine() : repeat_mode_(false), percent_mode_(false) {
+CalcEngine::CalcEngine()
+    : only_update_operation_(false), repeat_mode_(false), percent_mode_(false) {
 
     last_number_ = KNumber::Zero;
     error_ = false;
@@ -863,7 +863,11 @@
         }
     }
 
-    stack_.push(tmp_node);
+    if (getOnlyUpdateOperation() && !stack_.isEmpty() &&
+        !(func == FUNC_EQUAL || func == FUNC_PERCENT))
+        stack_.top().operation = func;
+    else
+        stack_.push(tmp_node);
 
     evalStack();
 }
@@ -903,8 +907,18 @@
     last_operation_ = FUNC_EQUAL;
     error_ = false;
     last_number_ = KNumber::Zero;
+    only_update_operation_ = false;
 
     stack_.clear();
 }
 
+void CalcEngine::setOnlyUpdateOperation(bool update)
+{
+    only_update_operation_ = update;
+}
+
+bool CalcEngine::getOnlyUpdateOperation() const
+{
+    return only_update_operation_;
+}