# Identify Halves, Thirds, and Fourths

Learning to identify halves, thirds, and fourths is a second grade, Common Core math skill: 2.G.3.  Below we show two videos that demonstrate this standard. Then, we provide a breakdown of the specific steps in the videos to help you teach your class.

Prior Learnings

Your students should be familiar with working with shapes, drawings, “manipulatives” and real-world objects.. In the first grade, students will have described and classified shapes based on their geometric attributes (1.G.1). Additionally, your students will have learned to distinguish between defining and non-defining attributes.

Future Learnings

Eventually, your students will apply these second grade concepts to further their understanding in future classes. Students will be able to connect the concept of equal groups to multiplication (3.OA.1). Students will be able to connect different shape categories and form relationships between categories and subcategories (3.G.1). Additionally, your students will understand how to use written fraction notations (3.NF.1, 3.G.2).

Common Core Standard: 2.G.3 - Partition circles and rectangles into two, three, or four equal shares, describe the shares, and recognize that equal shares of identical wholes do not need to have the same shape

Students who understand this principle can:

1. Recognize that dividing a shape evenly, multiple times, creates “equal shares.”
2. Learn that studying geometric relationships helps develop reasoning skills since shapes can explain parts of a whole and/or totals.
3. Partition shapes into equal shares: halves, thirds, or fourths.
4. Use different terms to identify equal parts.
5. Describe how equal shares might have different shapes.

Video 1: Partitioning Shapes into Equal Parts

The video starts by explaining that “shapes can be divided into equal parts. The math word is partitions.” Then, the video shows two circles, asking the viewers to identify which one has two partitions. Only one has partitions as the other is not divided equally.

Next, the video demonstrates how various shapes can be divided equally, showing that some shapes can be divided in different ways, and still be equal.

1. A square can be partitioned into halves in 3 ways.
a. Vertically, horizontally, and diagonally.
2. A square can be divided into fourths or quarters.
a. A vertical and horizontal line, and two diagonal lines.

The video then asks the viewers two questions.

1. How can one show 3 equal partitions on a square?
a. It shows 2 ways to divide a square into thirds.
2. How can one show 3 equal partitions on a circle?
a. The first example shows the wrong way to evenly divide a circle into thirds.
b. The second shows a correct way to divide a circle into thirds.

Then other shapes are shown and given partitions, and it reviews how many each shape has.

Video 2: Helping Sophia Partition a Chocolate Bar

The video starts out by helping Sophia divide her chocolate bar into halves, thirds, and fourths. Boddle asks viewers questions about the number of pieces she has after dividing the chocolate bar.

1. After Sophia divides it in half, she has 2 pieces.
2. After Sophia divides it in thirds, she has 3 pieces.
3. After Sophia divides it in fourths, she has 4 pieces.
4. Pieces should always be equal sizes.

The video then provides additional practice by having students identify which shape out of three is correctly partitioned into a specified number.

1. Out of 3 circles, which one is divided in thirds?
a. The second one is divided in thirds
2. Out of 3 squares, which one is divided into halves?
a. The third one is divided into halves.

The video ends by congratulating students on learning how to divide shapes into halves, thirds, and fourths.

Want more practice?