replace deprecated slash division with math division in Sass

Change-Id: I664c367e06eb166f74197ac50ef90dc24a7b5ef9
diff --git a/dev/scss/base/lengths.scss b/dev/scss/base/lengths.scss
index 9dd307d..c4a7e5a 100644
--- a/dev/scss/base/lengths.scss
+++ b/dev/scss/base/lengths.scss
@@ -1,3 +1,5 @@
+@use 'sass:math';
+
 /*
  * Defined lengths and sizes for the
  * Kalamar layout.
@@ -17,6 +19,6 @@
  */
 $standard-margin:     40px;
 $right-distance:      $standard-margin;
-$right-view-distance: $standard-margin / 2;
+$right-view-distance: math.div($standard-margin,2);
 $logo-left-distance:  230px;
-$footer-height:       100pt;
\ No newline at end of file
+$footer-height:       100pt;