diff -r 1376481f15e7 -r 033d51e026b0 emul/src/main/java/java/lang/AbstractStringBuilder.java
--- a/emul/src/main/java/java/lang/AbstractStringBuilder.java	Tue Oct 16 11:55:56 2012 +0200
+++ b/emul/src/main/java/java/lang/AbstractStringBuilder.java	Tue Oct 23 16:50:27 2012 +0200
@@ -657,7 +657,7 @@
      * @return  a reference to this object.
      */
     public AbstractStringBuilder append(float f) {
-        throw new UnsupportedOperationException();
+        return append(Float.toString(f));
     }
 
     /**
@@ -673,7 +673,7 @@
      * @return  a reference to this object.
      */
     public AbstractStringBuilder append(double d) {
-        throw new UnsupportedOperationException();
+        return append(Double.toString(d));
     }
 
     /**