rolling.html: Add information about units.

Text provided by Gary Wooding; thanks.

diff --git a/rolling.html b/rolling.html
index fbee44e..6adbf5c 100644 (file)
--- a/rolling.html
+++ b/rolling.html
@@ -183,6 +183,17 @@ calculator can’t understand what you’ve typed in an input
 box, or it’s hit trouble – usually this means that some
 necessary input is missing.
 
 box, or it’s hit trouble – usually this means that some
 necessary input is missing.
 

+<p>You specify the width and thickness of the strip you want, and the
+program calculates what size round or square wire you should start with.
+Additionally, if you specify the length of strip you need, it will
+calculate the length of the input wire.
+
+<p>You can use whatever units you like, as long as they are consistent,
+but you cannot use wire gauges.  If you use millimetres, the results
+will be in millimetres; if you use inches, the results will be in
+inches.  Whatever you use, the results are displayed to only 3 decimal
+places.
+

 </div>
 </body>
 </html>
 </div>
 </body>
 </html>