diff --git a/js/building/model/BuildingModel.js b/js/building/model/BuildingModel.js
index 3d66492..2be2884 100644
--- a/js/building/model/BuildingModel.js
+++ b/js/building/model/BuildingModel.js
@@ -25,7 +25,7 @@ define( require => {
   const ShapeGroup = require( 'FRACTIONS_COMMON/building/model/ShapeGroup' );
   const ShapeStack = require( 'FRACTIONS_COMMON/building/model/ShapeStack' );
   const Vector2 = require( 'DOT/Vector2' );
-
+// REVIEW: Doc for how scratchVector is used would be helpful.
   const scratchVector = new Vector2();
 
   class BuildingModel {
diff --git a/js/building/model/ShapePiece.js b/js/building/model/ShapePiece.js
index 9a18d7a..8c8199c 100644
--- a/js/building/model/ShapePiece.js
+++ b/js/building/model/ShapePiece.js
@@ -22,7 +22,7 @@ define( require => {
   const NumberProperty = require( 'AXON/NumberProperty' );
   const Property = require( 'AXON/Property' );
   const Vector2 = require( 'DOT/Vector2' );
-
+// REVIEW: Added doc about how this is used would be helpful
   let globalID = 0;
 
   class ShapePiece {
diff --git a/js/common/FractionsCommonConstants.js b/js/common/FractionsCommonConstants.js
index dbfd90e..89c5d51 100644
--- a/js/common/FractionsCommonConstants.js
+++ b/js/common/FractionsCommonConstants.js
@@ -8,10 +8,12 @@
 define( require => {
   'use strict';
 
+  // REVEIW: 'let' instead of 'var'
   // modules
   var fractionsCommon = require( 'FRACTIONS_COMMON/fractionsCommon' );
   var PhetFont = require( 'SCENERY_PHET/PhetFont' );
 
+  //REVIEW: Missing "// constants" notation
   var WHOLE_FRACTIONAL_SIZE_RATIO = 2;
   var SHAPE_RADIUS = 50;