diff --git a/inclassexercises.md b/inclassexercises.md
index 88801f8..3c0e33f 100644
--- a/inclassexercises.md
+++ b/inclassexercises.md
@@ -5,7 +5,7 @@ nav_order: 4
 ---
 To access these exercises, you must sign into your GEE account. After following the link, you will save your own version of the file to your GEOGXXXX repository. 
 
-## Class 2
+## Class 4
 Exercise 1: [Introduction to JavaScript](https://code.earthengine.google.com/5a5bbcb4c57bc7d1b2ed37be3ba9bfcb?hl=it)
 
 After this exercise, students should be able to:
@@ -14,7 +14,6 @@ After this exercise, students should be able to:
 - Declare multiple types of variables (string, numeric, list, object)
 - Use print statements
 
-## Class 3
 Exercise 2: [Introduction to GEE API](https://code.earthengine.google.com/cc96e647d6f192b2ea91c718a442c003?hl=it)
 
 After this exercise, students should be able to:
@@ -23,7 +22,7 @@ After this exercise, students should be able to:
 - Use logical operators
 - Sort, filter, count, and reduce lists
 
-## Class 4
+## Class 6
 Exercise 3: [Working with Images](https://code.earthengine.google.com/6ada11e98a2807310659f33d012cc0de?hl=it)
 
 After this exercise, students should be able to:
@@ -33,7 +32,6 @@ After this exercise, students should be able to:
 - Sort, filter, count, and reduce lists
 - Add an image to the GEE map and execute basic visualization tasks
   
-## Class 5
 Exercise 4: [Working with Image Collections](https://code.earthengine.google.com/978d9a16c6af7cbf24169328eb70a4b6?hl=it)
 
 After this exercise, students should be able to:
@@ -41,14 +39,13 @@ After this exercise, students should be able to:
 - Load an image collection
 - Filter an image collection based on a temporal, spatial, or variable query
   
-## Class 6
+## Class 8:
 Exercise 5: [Visualizing Single Bands](https://code.earthengine.google.com/d7f5a339665e3c5e73f301c438d8377d?hl=it)
 
 After this exercise, students should be able to:
 
 - Add visualization parameters to a single band image that determine min/max, color scheme, and opacity
 
-## Class 7:
 Exercise 6: [Visualizing Multiple Bands](https://code.earthengine.google.com/a50ddfbbe5c33a0919e922ea6f27d624?hl=it)
 
 After this exercise, students should be able to:
@@ -56,14 +53,13 @@ After this exercise, students should be able to:
 - Determine appropriate bands to visualize in a multiband image
 - Apply true color and false color composites to a multiband image
 
-## Class 8:
+## Class 10:
 Exercise 7: [Mosaics and Composites](https://code.earthengine.google.com/23febb4227ac4f75e6153cad9c93a815?hl=it)
 
 After this exercise, students should be able to:
 
 - Mosaic and composite separate images together
 
-## Class 9:
 Exercise 8: [Feature Collections, Clipping, Exporting Data](https://code.earthengine.google.com/0efe1af07f50a7335c74be9a00cbf9b2?hl=it)
 
 After this exercise, students should be able to:
@@ -72,7 +68,7 @@ After this exercise, students should be able to:
 - Clip an image
 - Export an image to Google Drive
 
-## Class 10: 
+## Class 12: 
 Exercise 9: [Mapping over an Image Collection](https://code.earthengine.google.com/fc889a7c127a768fc3536f00d91896a4?hl=it)
 
 After this exercise, students should be able to:
@@ -80,7 +76,7 @@ After this exercise, students should be able to:
 - Apply a function to each image in an image collection
 - Use reducers to create composite images from an image collection
 
-## Class 11:
+## Class 14:
 Exercise 10: [Reducers](https://code.earthengine.google.com/1250d5c38232855b86c342f8f7236843?hl=it)
 
 After this exercise, students should be able to:
@@ -88,7 +84,7 @@ After this exercise, students should be able to:
 - Reduce images and images collections based on feature boundaries
 
 
-## Class 13:
+## Class 16:
 Exercise 11: [Band Math](https://code.earthengine.google.com/20d1a6f63794c3cb4600497c78035f1d?hl=it)
 
 After this exercise, students should be able to:
@@ -96,15 +92,19 @@ After this exercise, students should be able to:
 - Add, subtract, multiply, and divide bands
 - Calculate common indices, including NDBI and NDVI
 
-## Class 15: 
+## Class 18: 
 Exercise 12: [Time Series](https://code.earthengine.google.com/541fcb4c0fec5d3a7be99663f7e5c739?hl=it)
 
 After this exercise, students should be able to:
 
-- 
+- Create a graphic that tracks a variable over a specified length of time in a specified location
 
-## Class 17:
+## Class 22:
 Exercise 13: [Change Detection](https://code.earthengine.google.com/4c916fbe34d82a8ba4f0b2ac594372e6?hl=it)
 
+After this exercise, students should be able to:
+
+- Determine a band math strategy to appropriately analyze change over time for a specific variable
+- Execute this strategy and visualize results