Index: modules/field/modules/number/number.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/field/modules/number/number.module,v
retrieving revision 1.44
diff -u -p -r1.44 number.module
--- modules/field/modules/number/number.module	22 Oct 2010 00:42:42 -0000	1.44
+++ modules/field/modules/number/number.module	22 Oct 2010 22:50:11 -0000
@@ -330,8 +330,9 @@ function number_field_widget_form(&$form
     '#default_value' => $value,
     // Allow a slightly larger size that the field length to allow for some
     // configurations where all characters won't fit in input field.
-    '#size' => $field['type'] == 'number_decimal' ? $field['settings']['precision'] + 2 : 12,
-    '#maxlength' => $field['type'] == 'number_decimal' ? $field['settings']['precision'] : 10,
+    '#size' => $field['type'] == 'number_decimal' ? $field['settings']['precision'] + 4 : 12,
+    // Allow two extra characters for signed values and decimal separator.
+    '#maxlength' => $field['type'] == 'number_decimal' ? $field['settings']['precision'] + 2 : 10,
     // Extract the number type from the field type name for easier validation.
     '#number_type' => str_replace('number_', '', $field['type']),
   );