Index: src/activities/memory-math-add-tux/resource/1/Data.qml
===================================================================
--- src/activities/memory-math-add-tux/resource/1/Data.qml
+++ src/activities/memory-math-add-tux/resource/1/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 11.")
-    difficulty: 1
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add-tux/resource/2/Data.qml
===================================================================
--- src/activities/memory-math-add-tux/resource/2/Data.qml
+++ src/activities/memory-math-add-tux/resource/2/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 12.")
-    difficulty: 2
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add-tux/resource/3/Data.qml
===================================================================
--- src/activities/memory-math-add-tux/resource/3/Data.qml
+++ src/activities/memory-math-add-tux/resource/3/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 13.")
-    difficulty: 3
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add-tux/resource/4/Data.qml
===================================================================
--- src/activities/memory-math-add-tux/resource/4/Data.qml
+++ src/activities/memory-math-add-tux/resource/4/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 14.")
-    difficulty: 3
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add-tux/resource/5/Data.qml
===================================================================
--- src/activities/memory-math-add-tux/resource/5/Data.qml
+++ src/activities/memory-math-add-tux/resource/5/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 15.")
-    difficulty: 3
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add-tux/resource/6/Data.qml
===================================================================
--- src/activities/memory-math-add-tux/resource/6/Data.qml
+++ src/activities/memory-math-add-tux/resource/6/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 16.")
-    difficulty: 4
+    difficulty: 5
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add-tux/resource/7/Data.qml
===================================================================
--- src/activities/memory-math-add-tux/resource/7/Data.qml
+++ src/activities/memory-math-add-tux/resource/7/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 17.")
-    difficulty: 4
+    difficulty: 5
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add-tux/resource/8/Data.qml
===================================================================
--- src/activities/memory-math-add-tux/resource/8/Data.qml
+++ src/activities/memory-math-add-tux/resource/8/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 18.")
-    difficulty: 4
+    difficulty: 5
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add/resource/1/Data.qml
===================================================================
--- src/activities/memory-math-add/resource/1/Data.qml
+++ src/activities/memory-math-add/resource/1/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 11.")
-    difficulty: 1
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add/resource/2/Data.qml
===================================================================
--- src/activities/memory-math-add/resource/2/Data.qml
+++ src/activities/memory-math-add/resource/2/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 12.")
-    difficulty: 2
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add/resource/3/Data.qml
===================================================================
--- src/activities/memory-math-add/resource/3/Data.qml
+++ src/activities/memory-math-add/resource/3/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 13.")
-    difficulty: 3
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add/resource/4/Data.qml
===================================================================
--- src/activities/memory-math-add/resource/4/Data.qml
+++ src/activities/memory-math-add/resource/4/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 14.")
-    difficulty: 3
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add/resource/5/Data.qml
===================================================================
--- src/activities/memory-math-add/resource/5/Data.qml
+++ src/activities/memory-math-add/resource/5/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 15.")
-    difficulty: 3
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add/resource/6/Data.qml
===================================================================
--- src/activities/memory-math-add/resource/6/Data.qml
+++ src/activities/memory-math-add/resource/6/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 16.")
-    difficulty: 4
+    difficulty: 5
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add/resource/7/Data.qml
===================================================================
--- src/activities/memory-math-add/resource/7/Data.qml
+++ src/activities/memory-math-add/resource/7/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 17.")
-    difficulty: 4
+    difficulty: 5
 
     data: [
         { // Level 1
Index: src/activities/memory-math-add/resource/8/Data.qml
===================================================================
--- src/activities/memory-math-add/resource/8/Data.qml
+++ src/activities/memory-math-add/resource/8/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Find cards with equivalent quantities until 18.")
-    difficulty: 4
+    difficulty: 5
 
     data: [
         { // Level 1
Index: src/activities/memory-math-mult/resource/1/Data.qml
===================================================================
--- src/activities/memory-math-mult/resource/1/Data.qml
+++ src/activities/memory-math-mult/resource/1/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Table of 1.")
-    difficulty: 1
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-mult/resource/10/Data.qml
===================================================================
--- src/activities/memory-math-mult/resource/10/Data.qml
+++ src/activities/memory-math-mult/resource/10/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Table of 10.")
-    difficulty: 6
+    difficulty: 5
 
     data: [
         { // Level 1
Index: src/activities/memory-math-mult/resource/2/Data.qml
===================================================================
--- src/activities/memory-math-mult/resource/2/Data.qml
+++ src/activities/memory-math-mult/resource/2/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Table of 2.")
-    difficulty: 2
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-mult/resource/3/Data.qml
===================================================================
--- src/activities/memory-math-mult/resource/3/Data.qml
+++ src/activities/memory-math-mult/resource/3/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Table of 3.")
-    difficulty: 3
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-mult/resource/4/Data.qml
===================================================================
--- src/activities/memory-math-mult/resource/4/Data.qml
+++ src/activities/memory-math-mult/resource/4/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Table of 4.")
-    difficulty: 3
+    difficulty: 4
 
     data: [
         { // Level 1
Index: src/activities/memory-math-mult/resource/6/Data.qml
===================================================================
--- src/activities/memory-math-mult/resource/6/Data.qml
+++ src/activities/memory-math-mult/resource/6/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Table of 6.")
-    difficulty: 4
+    difficulty: 5
 
     data: [
         { // Level 1
Index: src/activities/memory-math-mult/resource/9/Data.qml
===================================================================
--- src/activities/memory-math-mult/resource/9/Data.qml
+++ src/activities/memory-math-mult/resource/9/Data.qml
@@ -24,7 +24,7 @@
 
 Data {
     objective: qsTr("Table of 9.")
-    difficulty: 6
+    difficulty: 5
 
     data: [
         { // Level 1