diff --git a/examples/stocks/lib/stock_row.dart b/examples/stocks/lib/stock_row.dart
index 28e54980d67..4b8f47a65d8 100644
--- a/examples/stocks/lib/stock_row.dart
+++ b/examples/stocks/lib/stock_row.dart
@@ -47,7 +47,7 @@ class StockRow extends StatelessComponent {
       onLongPress: onLongPressed,
       child: new InkWell(
         child: new Container(
-          padding: const EdgeDims(16.0, 16.0, 20.0, 16.0),
+          padding: const EdgeDims.TRBL(16.0, 16.0, 20.0, 16.0),
           decoration: new BoxDecoration(
             border: new Border(
               bottom: new BorderSide(color: Theme.of(context).dividerColor)
diff --git a/packages/flutter/lib/src/painting/box_painter.dart b/packages/flutter/lib/src/painting/box_painter.dart
index 6126fcbb1e7..4fad4379027 100644
--- a/packages/flutter/lib/src/painting/box_painter.dart
+++ b/packages/flutter/lib/src/painting/box_painter.dart
@@ -14,9 +14,8 @@ import 'package:sky/src/painting/shadows.dart';
 /// Typically used for an offset from each of the four sides of a box. For
 /// example, the padding inside a box can be represented using this class.
 class EdgeDims {
-  // TODO(abarth): Remove this constructor or rename it to EdgeDims.fromTRBL.
   /// Constructs an EdgeDims from offsets from the top, right, bottom and left
-  const EdgeDims(this.top, this.right, this.bottom, this.left);
+  const EdgeDims.TRBL(this.top, this.right, this.bottom, this.left);
 
   /// Constructs an EdgeDims where all the offsets are value
   const EdgeDims.all(double value)
@@ -47,32 +46,89 @@ class EdgeDims {
 
   bool get isNonNegative => top >= 0.0 && right >= 0.0 && bottom >= 0.0 && left >= 0.0;
 
-  bool operator ==(other) {
-    if (identical(this, other))
-      return true;
-    return other is EdgeDims
-        && top == other.top
-        && right == other.right
-        && bottom == other.bottom
-        && left == other.left;
+  EdgeDims operator-(EdgeDims other) {
+    return new EdgeDims.TRBL(
+      top - other.top,
+      right - other.right,
+      bottom - other.bottom,
+      left - other.left
+    );
   }
 
   EdgeDims operator+(EdgeDims other) {
-    return new EdgeDims(top + other.top,
-                        right + other.right,
-                        bottom + other.bottom,
-                        left + other.left);
+    return new EdgeDims.TRBL(
+      top + other.top,
+      right + other.right,
+      bottom + other.bottom,
+      left + other.left
+    );
   }
 
-  EdgeDims operator-(EdgeDims other) {
-    return new EdgeDims(top - other.top,
-                        right - other.right,
-                        bottom - other.bottom,
-                        left - other.left);
+  EdgeDims operator*(double other) {
+    return new EdgeDims.TRBL(
+      top * other,
+      right * other,
+      bottom * other,
+      left * other
+    );
+  }
+
+  EdgeDims operator/(double other) {
+    return new EdgeDims.TRBL(
+      top / other,
+      right / other,
+      bottom / other,
+      left / other
+    );
+  }
+
+  EdgeDims operator~/(double other) {
+    return new EdgeDims.TRBL(
+      (top ~/ other).toDouble(),
+      (right ~/ other).toDouble(),
+      (bottom ~/ other).toDouble(),
+      (left ~/ other).toDouble()
+    );
+  }
+
+  EdgeDims operator%(double other) {
+    return new EdgeDims.TRBL(
+      top % other,
+      right % other,
+      bottom % other,
+      left % other
+    );
+  }
+
+  bool operator ==(other) {
+    return identical(this, other) ||
+      (other is EdgeDims &&
+       top == other.top &&
+       right == other.right &&
+       bottom == other.bottom &&
+       left == other.left);
+  }
+
+  /// Linearly interpolate between two EdgeDims
+  ///
+  /// If either is null, this function interpolates from [EdgeDims.zero].
+  static EdgeDims lerp(EdgeDims a, EdgeDims b, double t) {
+    if (a == null && b == null)
+      return null;
+    if (a == null)
+      return b * t;
+    if (b == null)
+      return a * (1.0 - t);
+    return new EdgeDims.TRBL(
+      sky.lerpDouble(a.top, b.top, t),
+      sky.lerpDouble(a.right, b.right, t),
+      sky.lerpDouble(a.bottom, b.bottom, t),
+      sky.lerpDouble(a.left, b.left, t)
+    );
   }
 
   /// An EdgeDims with zero offsets in each direction
-  static const EdgeDims zero = const EdgeDims(0.0, 0.0, 0.0, 0.0);
+  static const EdgeDims zero = const EdgeDims.TRBL(0.0, 0.0, 0.0, 0.0);
 
   int get hashCode {
     int value = 373;
@@ -142,7 +198,7 @@ class Border {
 
   /// The widths of the sides of this border represented as an EdgeDims
   EdgeDims get dimensions {
-    return new EdgeDims(top.width, right.width, bottom.width, left.width);
+    return new EdgeDims.TRBL(top.width, right.width, bottom.width, left.width);
   }
 
   int get hashCode {
diff --git a/packages/flutter/lib/src/widgets/binding.dart b/packages/flutter/lib/src/widgets/binding.dart
index fd005ad0fb9..792c6a161a0 100644
--- a/packages/flutter/lib/src/widgets/binding.dart
+++ b/packages/flutter/lib/src/widgets/binding.dart
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:async';
-
 import 'package:sky/animation.dart';
 import 'package:sky/rendering.dart';
 import 'package:sky/src/widgets/framework.dart';
diff --git a/packages/flutter/lib/src/widgets/dialog.dart b/packages/flutter/lib/src/widgets/dialog.dart
index b9b24ad8903..9098bebc1d4 100644
--- a/packages/flutter/lib/src/widgets/dialog.dart
+++ b/packages/flutter/lib/src/widgets/dialog.dart
@@ -70,7 +70,7 @@ class Dialog extends StatelessComponent {
     if (title != null) {
       EdgeDims padding = titlePadding;
       if (padding == null)
-        padding = new EdgeDims(24.0, 24.0, content == null ? 20.0 : 0.0, 24.0);
+        padding = new EdgeDims.TRBL(24.0, 24.0, content == null ? 20.0 : 0.0, 24.0);
       dialogBody.add(new Padding(
         padding: padding,
         child: new DefaultTextStyle(
@@ -83,7 +83,7 @@ class Dialog extends StatelessComponent {
     if (content != null) {
       EdgeDims padding = contentPadding;
       if (padding == null)
-        padding = const EdgeDims(20.0, 24.0, 24.0, 24.0);
+        padding = const EdgeDims.TRBL(20.0, 24.0, 24.0, 24.0);
       dialogBody.add(new Padding(
         padding: padding,
         child: new DefaultTextStyle(
diff --git a/packages/unit/test/painting/edge_dims_test.dart b/packages/unit/test/painting/edge_dims_test.dart
new file mode 100644
index 00000000000..bfcb4583f38
--- /dev/null
+++ b/packages/unit/test/painting/edge_dims_test.dart
@@ -0,0 +1,14 @@
+import 'package:sky/painting.dart';
+
+import 'package:test/test.dart';
+
+void main() {
+  test("EdgeDims.lerp()", () {
+    EdgeDims a = new EdgeDims.all(10.0);
+    EdgeDims b = new EdgeDims.all(20.0);
+    expect(EdgeDims.lerp(a, b, 0.25), equals(a * 1.25));
+    expect(EdgeDims.lerp(a, b, 0.25), equals(b * 0.625));
+    expect(EdgeDims.lerp(a, b, 0.25), equals(a + const EdgeDims.all(2.5)));
+    expect(EdgeDims.lerp(a, b, 0.25), equals(b - const EdgeDims.all(7.5)));
+  });
+}
diff --git a/packages/unit/test/rendering/size_test.dart b/packages/unit/test/rendering/size_test.dart
new file mode 100644
index 00000000000..76e84bcda2c
--- /dev/null
+++ b/packages/unit/test/rendering/size_test.dart
@@ -0,0 +1,18 @@
+import 'package:sky/rendering.dart';
+import 'package:test/test.dart';
+
+import 'rendering_tester.dart';
+
+void main() {
+  test('Stack can layout with top, right, bottom, left 0.0', () {
+    RenderBox box = new RenderConstrainedBox(
+      additionalConstraints: new BoxConstraints.tight(const Size(100.0, 100.0)));
+
+    layout(box, constraints: const BoxConstraints());
+
+    expect(box.size.width, equals(100.0));
+    expect(box.size.height, equals(100.0));
+    expect(box.size, equals(const Size(100.0, 100.0)));
+    expect(box.size.runtimeType.toString(), equals('_DebugSize'));
+  });
+}