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4th grade is the time to start really fine-tuning your arithmetic skills. Not only will you be a multi-digit addition and subtraction rockstar, but you'll extend the multiplication and division that you started in 3rd grade to several digits. You'll also discover that you sometimes have something left over (called a "remainder") when you divide. In 3rd grade you learned what a fraction is. Now you'll start adding, subtracting, multiplying, and comparing them. You'll also see how they relate to decimals. On other fronts, you'll learn how to convert between different units (which is super important when comparing the size and speed of robot unicorns in different countries) and continue your journey thinking about various shapes in two dimensions. Some of the foundational concepts of geometry (like lines, rays and angles) also get introduced. As always, we'll round this out with a healthy dose of applied word problems and explorations of number patterns and properties (including the ideas of factors, multiples and prime numbers). The fun must not stop! (Content was selected for this grade level based on a typical curriculum in the United States.)
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Geometry
Finally, we're getting to geometry. We've been waiting for this and hope you have been, too. The foundation of all geometry is the line--so that's a great place to start. From there we'll move into angles, quadrilaterals, and triangles. Our goal is here to get familiar with the basic concepts, skills, and applications of geometry. So jump in and let's go for a ride!
All content in “Geometry”

### Basic geometry: lines, line segments and rays

Let's draw points, lines, line segments, and rays. We'll also think about perpendicular and parallel lines and identify these in two-dimensional figures. Common Core Standard: 4.G.A.1

### Angles

What is an angle and how do we label, measure and construct them? Great question. Luckily we have all your answers! To begin our journey towards understanding angles, we'll learn terms like vertex, acute, obtuse, circle arc, circumference, and protractor. These basic angle concepts will get you on the road to angle domination! Common Core Standards: 4.MD.C.5, 4.MD.C.5a, 4.MD.C.5b, 4.MD.C.6, 4.MD.C.7, 4.G.A.1

### Interpreting and constructing angles

Now that we know what angles are, let's dig a bit deeper and classify them and understand their properties better. Acute, obtuse, right, adjacent--all are angles that we will be become familiar with. We'll all also examine how intersecting lines play a role. Lots of great stuff in this tutorial, so pull up a chair and get your angle on! Common Core Standards: 4.MD.C.7, 4.G.A.1

### Line of symmetry

A line of symmetry for a two-dimensional figure is a line across the figure such that the figure can be folded along the line into matching parts. In this tutorial, we'll identify line-symmetric figures and draw lines of symmetry. Common Core Standard: 4.G.A.3

### Classifying geometric shapes

In this tutorial, we'll classify two-dimensional figures based on the presence or absence of parallel or perpendicular lines, or the presence or absence of angles of a specified size. We'll also learn about special triangles called "right triangles". Common Core Standard: 4.G.A.2