diff --git a/files/images/Bubbles_speech.svg b/files/images/Bubbles_speech.svg
new file mode 100644
index 00000000..173ebf35
--- /dev/null
+++ b/files/images/Bubbles_speech.svg
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generator: Adobe Illustrator 19.1.0, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
+<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
+	 viewBox="0 0 480 480" style="enable-background:new 0 0 480 480;" xml:space="preserve">
+<style type="text/css">
+	.st0{fill:#FFFFFF;stroke:#000000;stroke-miterlimit:10;}
+	.st1{fill:none;stroke:#000000;stroke-miterlimit:10;}
+</style>
+<path class="st1" d="M220.1,222.2l-93.9,73.6l127.4-70.5c3.4,0.1,6.8,0.2,10.2,0.2c90.3,0,163.5-40.5,163.5-90.4
+	s-73.2-90.4-163.5-90.4S100.3,85.1,100.3,135C100.3,176.6,151,211.6,220.1,222.2L220.1,222.2z"/>
+</svg>
diff --git a/files/images/Bubbles_thought.svg b/files/images/Bubbles_thought.svg
new file mode 100644
index 00000000..c77ebca4
--- /dev/null
+++ b/files/images/Bubbles_thought.svg
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generator: Adobe Illustrator 19.1.0, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
+<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
+	 viewBox="0 0 480 480" style="enable-background:new 0 0 480 480;" xml:space="preserve">
+<style type="text/css">
+	.st0{fill:#FFFFFF;stroke:#000000;stroke-miterlimit:10;}
+	.st1{fill:none;stroke:#000000;stroke-miterlimit:10;}
+</style>
+<circle class="st1" cx="143.8" cy="268" r="22.6"/>
+<circle class="st1" cx="111.8" cy="313.2" r="13.2"/>
+<circle class="st1" cx="80.7" cy="334.2" r="7"/>
+<path class="st1" d="M293.8,49.9c3-1,6.4-1.9,9.7-1.9c16.8,0,30.4,13.6,30.4,30.4c0,1.9-0.2,3.7-0.5,5.5l0,0
+	c10.8,4.5,21,16.2,20.5,28.6c-0.4,9.1-1.2,18.8-11.3,27.7l0,0c8.5,6.8,8.7,29.6,4.7,39c-4.1,9.7-11.8,19.6-33.4,27.2
+	c-8.2,19.4-30.1,35.7-52.4,35.7c-9.6,0-18.9-2.5-26.7-6.9l0,0c-8.1,5.6-17.7,8.8-28.3,8.8c-18.9,0-35.8-10.6-44.4-26l0,0
+	c-22.5,0-45.3-15.3-49.5-36.6l0,0c-19.2-5.7-33.1-23.4-33.1-44.5c0-9.7,2.9-18.7,8-26.2l0,0c-2.7-5.5-4.2-11.8-4.2-18.3
+	c0-21.9,17.3-40,38.8-41.6l0,0c7.3-14.6,22.4-24.7,39.9-24.7c4.8,0,9.3,0.7,13.6,2.1l0,0c7.6-8.3,18.7-13.5,30.9-13.5
+	c12.8,0,24.2,5.7,31.9,14.8l0,0c6-4.7,13.6-7.6,21.7-7.6C277,22.1,290.5,33.9,293.8,49.9L293.8,49.9z"/>
+</svg>
diff --git a/topics/number_line.py b/topics/number_line.py
index 479805b3..6f56af6f 100644
--- a/topics/number_line.py
+++ b/topics/number_line.py
@@ -337,7 +337,7 @@ class NumberPlane(VMobject):
         return self
 
     def apply_function(self, function, maintain_smoothness = True):
-        SVGMobject.apply_function(self, function, maintain_smoothness = maintain_smoothness)
+        VMobject.apply_function(self, function, maintain_smoothness = maintain_smoothness)