diff --git a/src/addon/mod/assign/components/submission/addon-mod-assign-submission.html b/src/addon/mod/assign/components/submission/addon-mod-assign-submission.html
index 9d64740ec..1e8f391e9 100644
--- a/src/addon/mod/assign/components/submission/addon-mod-assign-submission.html
+++ b/src/addon/mod/assign/components/submission/addon-mod-assign-submission.html
@@ -149,7 +149,7 @@
                 <!-- Numeric grade. -->
                 <ion-item text-wrap *ngIf="grade.method == 'simple' && !grade.scale">
                     <ion-label stacked><h2>{{ 'addon.mod_assign.gradeoutof' | translate: {$a: gradeInfo.grade} }}</h2></ion-label>
-                    <ion-input *ngIf="!grade.disabled" type="number" [(ngModel)]="grade.grade" min="0" [max]="gradeInfo.grade" [lang]="grade.lang"></ion-input>
+                    <ion-input *ngIf="!grade.disabled" [type]="grade.type" [(ngModel)]="grade.grade" min="0" [max]="gradeInfo.grade" [lang]="grade.lang"></ion-input>
                     <p item-content *ngIf="grade.disabled">{{ 'addon.mod_assign.gradelocked' | translate }}</p>
                 </ion-item>
 
diff --git a/src/addon/mod/assign/components/submission/submission.ts b/src/addon/mod/assign/components/submission/submission.ts
index 3095a5212..4910b8603 100644
--- a/src/addon/mod/assign/components/submission/submission.ts
+++ b/src/addon/mod/assign/components/submission/submission.ts
@@ -472,7 +472,8 @@ export class AddonModAssignSubmissionComponent implements OnInit, OnDestroy {
             applyToAll: false,
             scale: false,
             lang: false,
-            disabled: false
+            disabled: false,
+            type: this.domUtils.numberInputSupportsComma() ? 'number' : 'text'
         };
 
         this.originalGrades =  {
@@ -506,7 +507,7 @@ export class AddonModAssignSubmissionComponent implements OnInit, OnDestroy {
             if (feedback.grade && feedback.grade.grade && !this.grade.grade) {
                 const parsedGrade = parseFloat(feedback.grade.grade);
                 this.grade.grade = parsedGrade || parsedGrade == 0 ? parsedGrade : null;
-                this.grade.gradebookGrade = this.grade.grade;
+                this.grade.gradebookGrade = this.utils.formatFloat(this.grade.grade);
                 this.originalGrades.grade = this.grade.grade;
             }
         } else {
@@ -585,7 +586,8 @@ export class AddonModAssignSubmissionComponent implements OnInit, OnDestroy {
                     if (data && (!feedback || !feedback.gradeddate || feedback.gradeddate < data.timemodified)) {
                         // If grade has been modified from gradebook, do not use offline.
                         if (this.grade.modified < data.timemodified) {
-                            this.grade.grade = data.grade;
+                            this.grade.grade = !this.grade.scale && this.grade.type == 'text' ?
+                                    this.utils.formatFloat(data.grade) : data.grade;
                             this.gradingStatusTranslationId = 'addon.mod_assign.gradenotsynced';
                             this.gradingColor = '';
                             this.originalGrades.grade = this.grade.grade;
@@ -772,8 +774,6 @@ export class AddonModAssignSubmissionComponent implements OnInit, OnDestroy {
                         userId: this.currentUserId
                     }, this.siteId);
                 });
-            }).catch((error) => {
-                this.domUtils.showErrorModalDefault(error, 'core.error', true);
             }).finally(() => {
                 // Select submission view.
                 this.tabs.selectTab(0);
@@ -802,6 +802,10 @@ export class AddonModAssignSubmissionComponent implements OnInit, OnDestroy {
         if (this.gradeInfo.scale) {
             this.grade.scale = this.utils.makeMenuFromList(this.gradeInfo.scale, this.translate.instant('core.nograde'));
         } else {
+            // If the grade uses a text input, format it.
+            this.grade.grade = this.grade.type == 'text' ? this.utils.formatFloat(this.grade.grade) : this.grade.grade;
+            this.originalGrades.grade = this.grade.grade;
+
             // Get current language to format grade input field.
             this.langProvider.getCurrentLanguage().then((lang) => {
                 this.grade.lang = lang;
@@ -829,11 +833,11 @@ export class AddonModAssignSubmissionComponent implements OnInit, OnDestroy {
 
                     // Not using outcomes or scale, get the numeric grade.
                     if (this.grade.scale) {
-                        this.grade.gradebookGrade = this.gradesHelper.getGradeValueFromLabel(
-                                this.grade.scale, grade.gradeformatted);
+                        this.grade.gradebookGrade = this.utils.formatFloat(this.gradesHelper.getGradeValueFromLabel(
+                                this.grade.scale, grade.gradeformatted));
                     } else {
                         const parsedGrade = parseFloat(grade.gradeformatted);
-                        this.grade.gradebookGrade = parsedGrade || parsedGrade == 0 ? parsedGrade : null;
+                        this.grade.gradebookGrade = parsedGrade || parsedGrade == 0 ? this.utils.formatFloat(parsedGrade) : null;
                     }
 
                     this.grade.disabled = grade.gradeislocked || grade.gradeisoverridden;
diff --git a/src/addon/mod/assign/pages/submission-review/submission-review.ts b/src/addon/mod/assign/pages/submission-review/submission-review.ts
index d6e39b6cd..be53916dc 100644
--- a/src/addon/mod/assign/pages/submission-review/submission-review.ts
+++ b/src/addon/mod/assign/pages/submission-review/submission-review.ts
@@ -15,6 +15,7 @@
 import { Component, OnInit, ViewChild } from '@angular/core';
 import { IonicPage, NavController, NavParams } from 'ionic-angular';
 import { CoreAppProvider } from '@providers/app';
+import { CoreDomUtilsProvider } from '@providers/utils/dom';
 import { CoreCourseProvider } from '@core/course/providers/course';
 import { AddonModAssignProvider } from '../../providers/assign';
 import { AddonModAssignSubmissionComponent } from '../../components/submission/submission';
@@ -44,7 +45,8 @@ export class AddonModAssignSubmissionReviewPage implements OnInit {
     protected forceLeave = false; // To allow leaving the page without checking for changes.
 
     constructor(navParams: NavParams, protected navCtrl: NavController, protected courseProvider: CoreCourseProvider,
-            protected appProvider: CoreAppProvider, protected assignProvider: AddonModAssignProvider) {
+            protected appProvider: CoreAppProvider, protected assignProvider: AddonModAssignProvider,
+            protected domUtils: CoreDomUtilsProvider) {
 
         this.moduleId = navParams.get('moduleId');
         this.courseId = navParams.get('courseId');
@@ -162,6 +164,8 @@ export class AddonModAssignSubmissionReviewPage implements OnInit {
                     this.forceLeave = true;
                     this.navCtrl.pop();
                 }
+            }).catch((error) => {
+                this.domUtils.showErrorModalDefault(error, 'core.error', true);
             });
         }
     }
diff --git a/src/providers/utils/dom.ts b/src/providers/utils/dom.ts
index 979a01980..c13a41b81 100644
--- a/src/providers/utils/dom.ts
+++ b/src/providers/utils/dom.ts
@@ -603,6 +603,15 @@ export class CoreDomUtilsProvider {
         return movedChildren;
     }
 
+    /**
+     * Check whether input number supports writing comma as a decimal separator.
+     *
+     * @return {boolean} Whether input number supports writing comma as a decimal separator.
+     */
+    numberInputSupportsComma(): boolean {
+        return !this.platform.is('android') || this.platform.version().major > 5;
+    }
+
     /**
      * Search and remove a certain element from inside another element.
      *
diff --git a/src/providers/utils/utils.ts b/src/providers/utils/utils.ts
index 408a4c950..acaca2707 100644
--- a/src/providers/utils/utils.ts
+++ b/src/providers/utils/utils.ts
@@ -471,7 +471,7 @@ export class CoreUtilsProvider {
      * @return {string} Locale float.
      */
     formatFloat(float: any): string {
-        if (typeof float == 'undefined') {
+        if (typeof float == 'undefined' || float === null) {
             return '';
         }