diff --git a/src/activities/digital_electricity/DigitalElectricity.qml b/src/activities/digital_electricity/DigitalElectricity.qml
--- a/src/activities/digital_electricity/DigitalElectricity.qml
+++ b/src/activities/digital_electricity/DigitalElectricity.qml
@@ -53,6 +53,9 @@
         }
 
         Keys.onPressed: {
+            if((event.key == Qt.Key_Return || event.key == Qt.Key_Enter) && okButton.enabled) {
+                Activity.checkAnswer()
+            }
             if (event.key == Qt.Key_Plus) {
                 Activity.zoomIn()
             }
@@ -178,7 +181,7 @@
                 horizontalAlignment: Text.AlignHLeft
                 width: Math.min(implicitWidth, 0.90 * parent.width)
                 height:  inputOutputTxt.visible == false ? Math.min(implicitHeight, 0.7 * parent.height) :
-                        Math.min(implicitHeight, (inputOutputTxt.inputs > 2 ? 0.3 : 0.4) * parent.height)
+                                                           Math.min(implicitHeight, (inputOutputTxt.inputs > 2 ? 0.3 : 0.4) * parent.height)
                 wrapMode: TextEdit.WordWrap
                 visible: false
                 z: 4
@@ -294,8 +297,8 @@
                         id: blueSquare
                         Rectangle {
                             width: ((index % truthTable.columns) / (truthTablesModel.inputs - 1)) <= 1 ?
-                                   (inputOutputTxt.inputs > 1 ? inputOutputTxt.maxWidth : inputOutputTxt.minSize) :
-                                   (inputOutputTxt.outputs > 1 ? inputOutputTxt.maxWidth : inputOutputTxt.minSize)
+                                       (inputOutputTxt.inputs > 1 ? inputOutputTxt.maxWidth : inputOutputTxt.minSize) :
+                                       (inputOutputTxt.outputs > 1 ? inputOutputTxt.maxWidth : inputOutputTxt.minSize)
                             height: inputOutputTxt.cellSize
                             border.color: "#373737"
                             border.width: 1
@@ -307,7 +310,7 @@
                                     return ((index % truthTable.columns) / (truthTablesModel.inputs - 1)) <= 1 ? "#A7D9F9" : "#A7F9DD"
                                 }
                             }
-                                   
+
                             GCText {
                                 id: truthTableValue
                                 anchors.centerIn: parent
@@ -335,8 +338,8 @@
             width: background.hori ?
                        background.width * 4 - items.toolsMargin : background.width * 4
             height: background.hori ?
-                       background.height * 4 - (bar.height * 1.1) :
-                       background.height * 4 - (bar.height * 1.1) - items.toolsMargin
+                        background.height * 4 - (bar.height * 1.1) :
+                        background.height * 4 - (bar.height * 1.1) - items.toolsMargin
             
             PinchArea {
                 id: pinchZoom
@@ -498,7 +501,7 @@
             }
             source: "qrc:/gcompris/src/core/resource/bar_ok.svg"
             sourceSize.width: 60 * ApplicationInfo.ratio
-
+            enabled: !tutorialInstruction.visible
             onClicked: Activity.checkAnswer()
         }