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 1e8f391e9..88260c55d 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
@@ -146,10 +146,10 @@
                     </a>
                 </ion-item>
 
-                <!-- Numeric grade. -->
+                <!-- Numeric grade. Use a text input because otherwise we cannot read the value if it has an invalid character. -->
                 <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]="grade.type" [(ngModel)]="grade.grade" min="0" [max]="gradeInfo.grade" [lang]="grade.lang"></ion-input>
+                    <ion-input *ngIf="!grade.disabled" type="text" [(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 4910b8603..b4a66e101 100644
--- a/src/addon/mod/assign/components/submission/submission.ts
+++ b/src/addon/mod/assign/components/submission/submission.ts
@@ -472,8 +472,7 @@ export class AddonModAssignSubmissionComponent implements OnInit, OnDestroy {
             applyToAll: false,
             scale: false,
             lang: false,
-            disabled: false,
-            type: this.domUtils.numberInputSupportsComma() ? 'number' : 'text'
+            disabled: false
         };
 
         this.originalGrades =  {
@@ -586,8 +585,7 @@ 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 = !this.grade.scale && this.grade.type == 'text' ?
-                                    this.utils.formatFloat(data.grade) : data.grade;
+                            this.grade.grade = !this.grade.scale ? this.utils.formatFloat(data.grade) : data.grade;
                             this.gradingStatusTranslationId = 'addon.mod_assign.gradenotsynced';
                             this.gradingColor = '';
                             this.originalGrades.grade = this.grade.grade;
@@ -735,7 +733,7 @@ export class AddonModAssignSubmissionComponent implements OnInit, OnDestroy {
             const attemptNumber = this.userSubmission ? this.userSubmission.attemptnumber : -1,
                 outcomes = {},
                 // Scale "no grade" uses -1 instead of 0.
-                grade = this.grade.scale && this.grade.grade == 0 ? -1 : this.utils.unformatFloat(this.grade.grade);
+                grade = this.grade.scale && this.grade.grade == 0 ? -1 : this.utils.unformatFloat(this.grade.grade, true);
 
             if (grade === false) {
                 // Grade is invalid.
@@ -802,8 +800,8 @@ 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;
+            // Format the grade.
+            this.grade.grade = this.utils.formatFloat(this.grade.grade);
             this.originalGrades.grade = this.grade.grade;
 
             // Get current language to format grade input field.
diff --git a/src/providers/utils/dom.ts b/src/providers/utils/dom.ts
index c13a41b81..979a01980 100644
--- a/src/providers/utils/dom.ts
+++ b/src/providers/utils/dom.ts
@@ -603,15 +603,6 @@ 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 acaca2707..bfe707092 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' || float === null) {
+        if (typeof float == 'undefined' || float === null || typeof float == 'boolean') {
             return '';
         }
 
@@ -1168,9 +1168,10 @@ export class CoreUtilsProvider {
      * Based on Moodle's unformat_float function.
      *
      * @param {any} localeFloat Locale aware float representation.
+     * @param {boolean} [strict] If true, then check the input and return false if it is not a valid number.
      * @return {any} False if bad format, empty string if empty value or the parsed float if not.
      */
-    unformatFloat(localeFloat: any): any {
+    unformatFloat(localeFloat: any, strict?: boolean): any {
         // Bad format on input type number.
         if (typeof localeFloat == 'undefined') {
             return false;
@@ -1189,18 +1190,17 @@ export class CoreUtilsProvider {
             return '';
         }
 
-        const localeSeparator = this.translate.instant('core.decsep');
-
         localeFloat = localeFloat.replace(' ', ''); // No spaces - those might be used as thousand separators.
-        localeFloat = localeFloat.replace(localeSeparator, '.');
+        localeFloat = localeFloat.replace(this.translate.instant('core.decsep'), '.');
+
+        const parsedFloat = parseFloat(localeFloat);
 
-        localeFloat = parseFloat(localeFloat);
         // Bad format.
-        if (isNaN(localeFloat)) {
+        if (strict && (!isFinite(localeFloat) || isNaN(parsedFloat))) {
             return false;
         }
 
-        return localeFloat;
+        return parsedFloat;
     }
 
     /**