Non Standard Units of Area| Solved Examples

Key Concepts

• Define unit square 
• How to measure area using non-standard units
• Define unit of area
• Types of standard units for area
• How to measure area using standard units
• Measuring area using standard units without unit squares

Introduction

Riya thinks about how to find the area of the blackboard using unit squares?

She placed unit squares on the blackboard.

1.1   Non-Standard Units of Area:

The size of the unit square determines the measurement of the area.

How to find the size of the unit square when area is given?

• James used the smaller unit square and found that the area of this shape is 18 square unit. If he used the larger unit square, what would the area of the shape be?

• 1 square unit
• square unit
• square unit
• square unit

How big is the Square unit?

Imagine you have a playroom with an area of 6 square units.

You need to cover that with a rubber mat.

How many rubber mats do you need to buy?

Knowing the number of square units, we cannot find the area; we need to know how big the unit square is.

So, let’s find unit of area 

What is Unit of Area?

A unit of area tells how much space a shape actually takes up .

Square millimeter is used for really small objects like a fingernail.

Square inch and square centimeter can be used for measuring small surfaces like papers, pictures, or drawings.

Square feet, square yard, and square meter are used for bigger spaces like areas of rooms, houses, gardens, and fields.

Square miles and square kilometers are used for really large areas of land. Hectares and acres are also used, but you’ll learn about them in later grades.

• By using standard units: 
  A larger unit takes fewer squares to cover the figure

A smaller unit takes more squares to cover the figure

• Here are shorter ways of writing these units of area:

               Square millimeter = mm²

               Square inch= in²

               Square centimeter = cm²

               Square feet = ft²

               Square yard = yd²

               Square meter = m²

How to write unit of areas?

• It’s important to use the right unit when measuring an area.

Example : Area of a house can be measure in square feet and square meters. 

Piece of paper is used in square cm and square inch.

Here are other units of area and their symbols:

We write unit of areas by adding a small 2 after the unit of length.

For example, square centimeter would be cm². It is read as square centimeters.

Area of regular shapes

How can we find area without unit squares?

Area can be found out by multiplying rows and columns using array method

Area =  Rows x columns

          =  3 cm x 8 cm

          =  24 cm²

For a square all sides are equal

 Rows = columns

Area = row x column

         = 5 m x 5 m

         = 25 m²

Assessment

Jim went to the park, and he found one football court and one basketball court? Can you help Jim in finding the areas of both the courts?  

Lets find the Area?

Concept Map :

What we have learnt:

• The area of a surface or a plane figure is the number of square units needed to cover the surface of the figure.         
• Area is measured in square units.
• Unit Square : Each side of the square is 1 unit.
• Unit squares can be of different sizes.
• The size of the unit square determines the measurement of the area.
• A unit of area tells how much space a shape actually takes up.
• Square millimeter is used for very small areas.
• Square inch and square centimeter are used for small surfaces.
• Square feet, square yard, and square meter are used for bigger spaces.
• Square miles and square kilometers are used for very big areas.