--- math-display.c	2012-04-06 23:05:54.918167253 +0530
+++ ../math-display.c	2012-04-07 00:38:53.651790772 +0530
@@ -115,8 +115,8 @@
     state = event->state & (GDK_CONTROL_MASK | GDK_MOD1_MASK);
     c = gdk_keyval_to_unicode(event->keyval);
 
-    /* Solve on enter */
-    if (event->keyval == GDK_KEY_Return || event->keyval == GDK_KEY_KP_Enter) {
+    /* Solve on enter and on Equals button. */
+    if (event->keyval == GDK_KEY_Return || event->keyval == GDK_KEY_KP_Enter || event->keyval == GDK_KEY_KP_Equal) {
         math_equation_solve(display->priv->equation);
         return TRUE;
     }
