diff --git a/src/proxy-animation.js b/src/proxy-animation.js
index 986fedd..8fe353f 100644
--- a/src/proxy-animation.js
+++ b/src/proxy-animation.js
@@ -6,6 +6,7 @@ import {
   fractionalOffset,
 } from "./scroll-timeline-base";
 import {splitIntoComponentValues} from './utils';
+import {simplifyCalculation} from './simplify-calculation';
 
 const nativeDocumentGetAnimations = document.getAnimations;
 const nativeElementGetAnimations = window.Element.prototype.getAnimations;
@@ -823,19 +824,19 @@ function createProxyEffect(details) {
 // Computes the start delay as a fraction of the active cover range.
 function fractionalStartDelay(details) {
   if (!details.animationRange) return 0;
-  if (details.animationRange.start === 'normal') {
-    details.animationRange.start = getNormalStartRange(details.timeline);
-  }
-  return fractionalOffset(details.timeline, details.animationRange.start);
+  const rangeStart = details.animationRange.start === 'normal' ?
+    getNormalStartRange(details.timeline) :
+    details.animationRange.start;
+  return fractionalOffset(details.timeline, rangeStart);
 }
 
 // Computes the ends delay as a fraction of the active cover range.
 function fractionalEndDelay(details) {
   if (!details.animationRange) return 0;
-  if (details.animationRange.end === 'normal') {
-    details.animationRange.end = getNormalEndRange(details.timeline);
-  }
-  return 1 - fractionalOffset(details.timeline, details.animationRange.end);
+  const rangeEnd = details.animationRange.end === 'normal' ?
+    getNormalEndRange(details.timeline) :
+    details.animationRange.end;
+  return 1 - fractionalOffset(details.timeline, rangeEnd);
 }
 
 // Map from an instance of ProxyAnimation to internal details about that animation.
@@ -957,8 +958,8 @@ function getNormalEndRange(timeline) {
 
 function parseAnimationRange(timeline, value) {
   const animationRange = {
-    start: getNormalStartRange(timeline),
-    end: getNormalEndRange(timeline),
+    start: 'normal',
+    end: 'normal',
   };
 
   if (!value)
@@ -1048,11 +1049,11 @@ function parseTimelineRangePart(timeline, value, position) {
         if (ANIMATION_RANGE_NAMES.includes(parts[0])) {
           rangeName = parts[0];
         } else {
-          offset = CSSNumericValue.parse(parts[0]);
+          offset = simplifyCalculation(CSSNumericValue.parse(parts[0]), {});
         }
       } else if (parts.length === 2) {
         rangeName = parts[0];
-        offset = CSSNumericValue.parse(parts[1]);
+        offset = simplifyCalculation(CSSNumericValue.parse(parts[1]), {});
       }
     }
 
diff --git a/test/expected.txt b/test/expected.txt
index d7913de..3a8a9ae 100644
--- a/test/expected.txt
+++ b/test/expected.txt
@@ -1054,7 +1054,7 @@ FAIL	/scroll-animations/view-timelines/timeline-offset-in-keyframe.html	Timeline
 FAIL	/scroll-animations/view-timelines/timeline-offset-in-keyframe.html	Timeline offsets in programmatic keyframes resolved when updating the animation effect
 FAIL	/scroll-animations/view-timelines/unattached-subject-inset.html	Creating a view timeline with a subject that is not attached to the document works as expected
 FAIL	/scroll-animations/view-timelines/view-timeline-get-current-time-range-name.html	View timeline current time for named range
-FAIL	/scroll-animations/view-timelines/view-timeline-get-set-range.html	Getting and setting the animation range
+PASS	/scroll-animations/view-timelines/view-timeline-get-set-range.html	Getting and setting the animation range
 PASS	/scroll-animations/view-timelines/view-timeline-inset.html	View timeline with px based inset.
 PASS	/scroll-animations/view-timelines/view-timeline-inset.html	View timeline with percent based inset.
 PASS	/scroll-animations/view-timelines/view-timeline-inset.html	view timeline with inset auto.