Grade 3
  1. Number Sense and Numeration  1.1. Understanding Numbers  1.1.1. Reading and Writing Numbers up to 10,000  1.1.2. Place Value up to Thousands  1.1.3. Comparing and Ordering Numbers  1.1.4. Rounding Numbers to the Nearest Ten and Hundred  1.1.5. Skip Counting by 2s, 5s, 10s, and 100s up to 1,000  1.2. Operations with Whole Numbers  1.2.1. Addition and Subtraction up to 1,000  1.2.2. Multiplication Facts (up to 10 x 10)  1.2.3. Division Facts (up to 100)  1.2.4. Multiplication as Repeated Addition  1.2.5. Division as Equal Sharing  1.2.6. Word Problems with Addition, Subtraction, Multiplication, and Division  1.3. Estimation  1.3.1. Estimating Sums and Differences  1.3.2. Estimating Products and Quotients  1.4. Understanding Even and Odd Numbers
  2. Fractions and Decimals  2.1. Understanding Fractions  2.1.1. Identifying and Representing Fractions  2.1.2. Fractions of a Whole and Part of a Set  2.1.3. Comparing and Ordering Fractions with Like Denominators  2.1.4. Equivalent Fractions  2.1.5. Simple Fraction Word Problems  2.2. Introduction to Decimals  2.2.1. Tenths and Hundredths as Decimals  2.2.2. Relationship between Fractions and Decimals
  3. Measurement  3.1. Length  3.1.1. Measuring in Centimeters and Meters  3.1.2. Comparing and Ordering Lengths  3.1.3. Estimating Lengths  3.1.4. Converting Between Centimeters and Meters  3.2. Mass  3.2.1. Measuring in Grams and Kilograms  3.2.2. Estimating and Comparing Mass  3.3. Capacity  3.3.1. Measuring in Milliliters and Liters  3.3.2. Estimating and Comparing Capacity  3.4. Time  3.4.1. Telling Time to the Nearest Minute  3.4.2. Calculating Elapsed Time  3.4.3. Using a Calendar  3.4.4. Understanding A.M. and P.M.  3.5. Area and Perimeter  3.5.1. Calculating Perimeter of Simple Shapes  3.5.2. Estimating and Measuring Area of Shapes  3.5.3. Finding Area by Counting Squares
  4. Geometry  4.1. Properties of Shapes  4.1.1. Identifying 2D Shapes (Triangles, Quadrilaterals, Circles, etc.)  4.1.2. Identifying 3D Shapes (Cubes, Spheres, Cylinders, etc.)  4.1.3. Describing Attributes of 2D and 3D Shapes  4.1.4. Recognizing Parallel and Perpendicular Lines  4.2. Symmetry and Transformations  4.2.1. Recognizing Lines of Symmetry  4.2.2. Identifying Flips, Slides, and Turns  4.3. Angles  4.3.1. Understanding Right Angles  4.3.2. Comparing Angles (Acute, Right, Obtuse)
  5. Data Management and Probability  5.1. Data Collection and Organization  5.1.1. Collecting Data using Surveys and Experiments  5.1.2. Organizing Data using Tally Charts and Tables  5.2.1. Creating and Interpreting Pictographs  5.2.2. Creating and Interpreting Bar Graphs  5.2.3. Reading Simple Line Graphs  5.3. Probability  5.3.1. Understanding Basic Probability Terms (Certain, Possible, Impossible)  5.3.2. Predicting Outcomes  5.3.3. Simple Probability Experiments
  6. Patterns and Algebra  6.1. Patterns  6.1.1. Identifying and Extending Numeric Patterns  6.1.2. Identifying and Extending Shape Patterns  6.1.3. Creating Patterns Using Rules  6.2. Introduction to Algebra  6.2.1. Understanding Variables as Unknowns  6.2.2. Solving Simple Addition and Subtraction Equations  6.2.3. Using Patterns to Solve Problems
  7. Problem-Solving Skills  7.1. Strategies for Problem-Solving  7.1.1. Using Pictures or Diagrams  7.1.2. Identifying Patterns in Problems  7.1.3. Making Organized Lists  7.1.4. Guessing and Checking  7.1.5. Using Logical Reasoning  7.1.6. Breaking Down Problems into Steps

Grade 3 → Measurement ↓


Area and Perimeter


In math, and especially when you're in grade 3, it's very important to understand how to measure things. Knowing how to measure helps us know how big or small something is and how much space it takes up. This is where "area" and "perimeter" come into play. Let's understand these two ideas in a way that's simple and easy to understand.

What is the perimeter?

The perimeter is the distance around the outside of a shape. You can think of it like a fence around a garden. If you want to put a fence around your yard, the total length of the fence will be the perimeter.

For example, let's say we have a rectangle like this:

   ,
   ,
   ,

To find the perimeter, add up all the sides. If the top is 5 units, the bottom is also 5 units. If one side is 3 units, the other side is also 3 units (because rectangles have opposite sides that are the same length).

The formula for the perimeter of a rectangle is:

Perimeter = 2 x (Length + Width)

For our rectangle:

Perimeter = 2 x (5 + 3) = 2 x 8 = 16 units

What is the area?

Area is the size of the surface of a shape. Basically, it's a measure of how much space is inside a shape. If you want to cover your rectangle with tiles, the number of tiles it takes to cover it will be its area.

Let us take the example of this verse:

   ,
   ,
   ,

To find the area of a rectangle, multiply the length by the width. The formula is:

Area = Length x Width

Using our rectangle values:

Area = 5 x 3 = 15 square units

Perimeter examples

Example 1: Square

In a square, all sides are equal. If one side of a square is 4 units:

   ,
   ,
   ,

The perimeter is:

Perimeter = 4 x 4 = 16 units

Example 2: Triangle

Consider a triangle with sides 3 units, 4 units and 5 units:

    ,
   ,
  ,

The perimeter is:

Perimeter = 3 + 4 + 5 = 12 units

Examples of the field

Example 1: Square

For a square with a side of 4 units:

   ,
   ,
   ,

This area is:

Area = 4 x 4 = 16 square units

Example 2: Triangle (right angle)

For a right triangle where the base is 3 units and the height is 4 units:

    ,
   ,
  ,

The area is given by the following formula:

Area = (Base x Height) / 2

Substitute the values into the formula:

Area = (3 x 4) / 2 = 12 / 2 = 6 square units

Importance of units

While measuring area and perimeter, it is necessary to use the correct units. If we are measuring in meters, the perimeter will be in meters and the area will be in square meters. The same rule applies to units like centimeters, feet, yards, etc.

Finding the perimeter: Step by step

Let's learn more about how to calculate the perimeter of different shapes using simple step-by-step instructions. We can start with some of the most common shapes.

1. Rectangle:

For a rectangle, add the length and the width, then double it because a rectangle has two pairs of equal sides.

Perimeter = 2 x (Length + Width)

2. Class:

A square has four equal sides, so multiply the length of one side by four.

Perimeter = 4 x Side

3. Triangle:

Simply add the lengths of the three sides together.

Perimeter = Side1 + Side2 + Side3

Calculating area: Step by step

Now let's see how we can find the area of various shapes using simple calculations and formulas.

1. Rectangle:

Multiply the length by the width.

Area = Length x Width

2. Class:

Since all sides are equal, multiply one side by itself.

Area = Side x Side

3. Triangle (right angle):

Multiply the base by the height and divide by 2.

Area = (Base x Height) / 2

Practice problems

Let's practice some problems to strengthen our understanding:

Problem 1: Find the perimeter of a rectangle

The length of a rectangle is 6 units and the width is 3 units. What is its perimeter?

Perimeter = 2 x (Length + Width) = 2 x (6 + 3) = 2 x 9 = 18 units

Problem 2: Find the area of the square

The sides of a square are 5 units. What is its area?

Area = Side x Side = 5 x 5 = 25 square units

Problem 3: Find the perimeter of a triangle

The sides of a triangle are 4 units, 5 units and 6 units. What is the perimeter?

Perimeter = Side1 + Side2 + Side3 = 4 + 5 + 6 = 15 units

Problem 4: Find the area of a right-angled triangle

The base of a right-angled triangle is 8 units and the height is 4 units. What is its area?

Area = (Base x Height) / 2 = (8 x 4) / 2 = 32 / 2 = 16 square units

Conclusion

Understanding the concepts of area and perimeter is essential for solving real-world problems. It is important to remember that perimeter is about the distance around the shape and area is about the space inside the shape. With practice, these calculations become easier, and you can handle more complex shapes with confidence.


Grade 3 → 3.5


U
username
0%
completed in Grade 3

← Prev (3.4.4)
Understanding A.M. and P.M.
Next (3.5.1) →
Calculating Perimeter of Simple Shapes

Comments 



Area and Perimeter

https://www.buddymath.com/g3/3.5?bmal=en