diff --git a/src/main/java/org/apache/commons/math/linear/AbstractRealMatrix.java b/src/main/java/org/apache/commons/math/linear/AbstractRealMatrix.java
index 85aa85c62..1500a8bee 100644
--- a/src/main/java/org/apache/commons/math/linear/AbstractRealMatrix.java
+++ b/src/main/java/org/apache/commons/math/linear/AbstractRealMatrix.java
@@ -564,10 +564,16 @@ public abstract class AbstractRealMatrix
     public abstract void setEntry(int row, int column, double value);
 
     /** {@inheritDoc} */
-    public abstract void addToEntry(int row, int column, double increment);
+    public void addToEntry(int row, int column, double increment) {
+        MatrixUtils.checkMatrixIndex(this, row, column);
+        setEntry(row, column, getEntry(row, column) + increment);
+    }
 
     /** {@inheritDoc} */
-    public abstract void multiplyEntry(int row, int column, double factor);
+    public void multiplyEntry(int row, int column, double factor) {
+        MatrixUtils.checkMatrixIndex(this, row, column);
+        setEntry(row, column, getEntry(row, column) * factor);
+    }
 
     /** {@inheritDoc} */
     public RealMatrix transpose() {
diff --git a/src/site/xdoc/changes.xml b/src/site/xdoc/changes.xml
index 5542670ec..bf13163d4 100644
--- a/src/site/xdoc/changes.xml
+++ b/src/site/xdoc/changes.xml
@@ -52,6 +52,10 @@ The <action> type attribute can be add,update,fix,remove.
     If the output is not quite correct, check for invisible trailing spaces!
      -->
     <release version="3.0" date="TBD" description="TBD">
+      <action dev="erans" type="update" issue="MATH-696">
+        Default implementation for "addToEntry" and "multiplyEntry" in
+        "AbstractRealMatrix".
+      </action>
       <action dev="erans" type="add" issue="MATH-685">
         Method "addToEntry" in "RealVector".
       </action>