address a comment

Co-authored-by: Gina Peter Banyard <[email protected]>

Author: SakiTakamachi

reference/bc/bcmath.number.xml

@@ -8,11 +8,12 @@
  <partintro>
   <section xml:id="bcmath-number.intro">
    &reftitle.intro;
-   <para>
-    A class for an arbitrary precision number. These objects support overloaded
+   <simpara>
+    A class for an arbitrary precision number.
+    These objects support overloaded
     <link linkend="language.operators.arithmetic">arithmetic</link> and
     <link linkend="language.operators.comparison">comparison</link> operators.
-   </para>
+   </simpara>
 
    <note>
     <simpara>This class is not affected by <parameter>bcmath.scale</parameter> in &php.ini;.</simpara>