diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/NumericFormatterBase.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/NumericFormatterBase.php
index 27bb234..c240fab 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/NumericFormatterBase.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/NumericFormatterBase.php
@@ -78,6 +78,8 @@ public function viewElements(FieldItemListInterface $items) {
         $suffix = (count($suffixes) > 1) ? format_plural($item->value, $suffixes[0], $suffixes[1]) : $suffixes[0];
         $output = $prefix . $output . $suffix;
       }
+      // Output the raw value in a content attribute if the text of the HTML
+      // element differs from the raw value (for example when a prefix is used).
       if ($item->value != $output) {
         if (!empty($item->_attributes)) {
           $item->_attributes += array('content' => $item->value);
diff --git a/core/modules/rdf/src/Tests/Field/FieldRdfaTestBase.php b/core/modules/rdf/src/Tests/Field/FieldRdfaTestBase.php
index c0bd8b9..a8761f7 100644
--- a/core/modules/rdf/src/Tests/Field/FieldRdfaTestBase.php
+++ b/core/modules/rdf/src/Tests/Field/FieldRdfaTestBase.php
@@ -134,7 +134,7 @@ protected function getAbsoluteUri($entity) {
   }
 
   /**
-   * Parse a content and return the html element.
+   * Parses a content and return the html element.
    *
    * @param string $content
    *   The html to parse.
diff --git a/core/modules/rdf/src/Tests/Field/NumberFieldRdfaTest.php b/core/modules/rdf/src/Tests/Field/NumberFieldRdfaTest.php
index eb63059..ae094bb 100644
--- a/core/modules/rdf/src/Tests/Field/NumberFieldRdfaTest.php
+++ b/core/modules/rdf/src/Tests/Field/NumberFieldRdfaTest.php
@@ -22,7 +22,7 @@ public function testIntegerFormatter() {
     $this->fieldType = 'integer';
     $testValue = 3;
     $this->createTestField();
-    $this->createTestEntity();
+    $this->createTestEntity($testValue);
     $this->assertFormatterRdfa(array('type' => $this->fieldType), 'http://schema.org/baseSalary', array('value' => $testValue));
 
     // Test that the content attribute is not created.
@@ -48,7 +48,7 @@ public function testIntegerFormatterWithSettings() {
       'suffix' => ' llamas.',
     );
     $this->createTestField($field_instance_settings);
-    $this->createTestEntity();
+    $this->createTestEntity($testValue);
     $this->assertFormatterRdfa($formatter, 'http://schema.org/baseSalary', array('value' => $testValue));
 
     // Test that the content attribute is created.
@@ -63,7 +63,7 @@ public function testFloatFormatter() {
     $this->fieldType = 'float';
     $testValue = 3.33;
     $this->createTestField();
-    $this->createTestEntity();
+    $this->createTestEntity($testValue);
     $this->assertFormatterRdfa(array('type' => $this->fieldType), 'http://schema.org/baseSalary', array('value' => $testValue));
 
     // Test that the content attribute is not created.
@@ -90,7 +90,7 @@ public function testFloatFormatterWithSettings() {
       'suffix' => ' more.',
     );
     $this->createTestField($field_instance_settings);
-    $this->createTestEntity();
+    $this->createTestEntity($testValue);
     $this->assertFormatterRdfa($formatter, 'http://schema.org/baseSalary', array('value' => $testValue));
 
     // Test that the content attribute is created.
@@ -99,7 +99,7 @@ public function testFloatFormatterWithSettings() {
   }
 
   /**
-   * Tests the float formatter with a scale.
+   * Tests the float formatter with a scale. Scale is not exercised.
    */
   public function testFloatFormatterWithScale() {
     $this->fieldType = 'float';
@@ -111,7 +111,7 @@ public function testFloatFormatterWithScale() {
     );
     $testValue = 3.33;
     $this->createTestField();
-    $this->createTestEntity();
+    $this->createTestEntity($testValue);
     $this->assertFormatterRdfa($formatter, 'http://schema.org/baseSalary', array('value' => $testValue));
 
     // Test that the content attribute is not created.
@@ -120,17 +120,38 @@ public function testFloatFormatterWithScale() {
   }
 
   /**
+   * Tests the float formatter with a scale. Scale is exercised.
+   */
+  public function testFloatFormatterWithScaleExercised() {
+    $this->fieldType = 'float';
+    $formatter = array(
+      'type' => $this->fieldType,
+      'settings' => array(
+        'scale' => 5,
+      ),
+    );
+    $testValue = 3.1234567;
+    $this->createTestField();
+    $this->createTestEntity($testValue);
+    $this->assertFormatterRdfa($formatter, 'http://schema.org/baseSalary', array('value' => $testValue));
+
+    // Test that the content attribute is created.
+    $result = $this->xpathContent($this->getRawContent(), '//div[contains(@class, "field-item") and @content=:testValue]', array(':testValue' => $testValue));
+    $this->assertTrue($result);
+  }
+
+  /**
    * Tests the decimal formatter.
    */
   public function testDecimalFormatter() {
     $this->fieldType = 'decimal';
     $testValue = 3.33;
     $this->createTestField();
-    $this->createTestEntity();
+    $this->createTestEntity($testValue);
     $this->assertFormatterRdfa(array('type' => $this->fieldType), 'http://schema.org/baseSalary', array('value' => $testValue));
 
     // Test that the content attribute is not created.
-    $result = $this->xpathContent($this->getRawContent(), '//div[contains(@class, "field-item") and @content]', array(':testValue' => $testValue));
+    $result = $this->xpathContent($this->getRawContent(), '//div[contains(@class, "field-item") and @content]');
     $this->assertFalse($result);
   }
 
@@ -153,7 +174,7 @@ public function testDecimalFormatterWithSettings() {
       'suffix' => ' more.',
     );
     $this->createTestField($field_instance_settings);
-    $this->createTestEntity();
+    $this->createTestEntity($testValue);
     $this->assertFormatterRdfa($formatter, 'http://schema.org/baseSalary', array('value' => $testValue));
 
     // Test that the content attribute is created.
@@ -164,7 +185,7 @@ public function testDecimalFormatterWithSettings() {
   /**
    * Creates the RDF mapping for the field.
    */
-  protected function createTestEntity() {
+  protected function createTestEntity($testValue) {
     // Add the mapping.
     $mapping = rdf_get_mapping('entity_test', 'entity_test');
     $mapping->setFieldMapping($this->fieldName, array(