CONFIDENTIAL 1 Area and Perimeter Grade 4. CONFIDENTIAL 2 Let’s warm up : Fill in the blanks: 1)____ gram (g) = 43,000 milligrams (mg) 2) ____ kilogram.

CONFIDENTIAL 1

Area and Perimeter

Grade 4

CONFIDENTIAL 2

Let’s warm up :

Fill in the blanks:

1) ____ gram (g) = 43,000 milligrams (mg)

2) ____ kilogram (kg) = 79,000 grams (g)

3) 75 gram (g) = _____ milligrams (mg)

4) 69 kilogram (kg) = _____ grams (g)

CONFIDENTIAL 3

Let’s review what we did in the previous chapter

MASS: It is the amount of matter that makes up an object.The mass of a math book is 1 kilogram.

Customary Units are used in US. Metric Units are used by most countries.

Metric Units of Mass

1 gram (g) = 1,000 milligrams (mg)

1 kilogram (kg) = 1,000 grams (g)

Simple Conversion Tables

CONFIDENTIAL 4

Review

Convert grams to milligrams

To change to a smaller unit, multiply.

Example: How many milligrams is 4 grams?

We are given,

4 grams = __ milligrams 4 x 1,000 = 4,000

4 grams = 4,000 milligrams

4 grams is equal to 4,000 milligrams .

CONFIDENTIAL 5

Review

Convert milligrams to grams

To change to a Larger unit, divide.

Example: How many grams is 5,000 milligrams ?

We are given,

5,000 milligrams = __ grams5,000 ÷ 1000 = 5

5,000 milligrams = 5 grams

5,000 milligrams is equal to 5 grams.

CONFIDENTIAL 6

Review

Convert kilograms to grams

To change to a smaller unit, multiply.

Example: How many grams is 4 kilograms?

We are given,

4 kilograms = __ grams 4 x 1,000 = 4,000

4 kilograms = 4,000 grams

4 kilograms is equal to 4,000 grams .

CONFIDENTIAL 7

Review

Convert grams to kilograms

To change to a Larger unit, divide.

Example: How many kilograms is 5,000 grams ?

We are given,

5,000 grams = __ kilograms5,000 ÷ 1000 = 5

5,000 grams = kilograms

5,000 grams is equal to 5 kilograms.

CONFIDENTIAL 8

Today we will learn about the Area and perimeter

PERIMETER: It is the distance around a figure.

Area and perimeter are geometric measurements used to measure plane figures.

The perimeter

of the triangle is

3 cms.

1 cm

1 cm

1 cm

CONFIDENTIAL 9

AREA: is the number of square units needed to cover a plane figure.

2 cm

2 cm

The area of the square is 4 cms2.

Use a formula

Area of the square= side x side = 2cm x 2cm=.4 square centimeters

(cm2)

CONFIDENTIAL 10

PERIMETER: is computed by adding the lengths of the figure's sides.

For example:We see a hexagon.

2 cm

3 c

m3 c

m

We are supposed to find the perimeter of the hexagon.

CONFIDENTIAL 11

2 cm

3 c

m3 c

m

Add the lengths of the hexagon's sides.

Perimeter (P)

= 2 cm + 3 cm + 3 cm + 2 cm + 3 cm + 3 cm

= 16 cm

The perimeter of the given hexagon is 16 cm.

CONFIDENTIAL 12

AREA: is computed by counting the number of square units or use a formula.

Counting the squares1

cm

1 cm

Count the number of shaded centimeter squares.

There are 6 square centimeters (cm2).

CONFIDENTIAL 13

1 cm

1 cm

Use a formula

Multiply the length times the width to find the area.

Area of the rectangle= length x width= 2cm x 3 cm=.6 square centimeters

(cm2)

CONFIDENTIAL 14

Area of a complex figure

Find the area of the green portion

1 cm

1 cm

STEP1:

Divide the figure into rectangle or square.

CONFIDENTIAL 15

STEP2:

Find the area of each smaller figure.Area of green rectangle

= 3 x 6 = 18 cm2

Area of blue rectangle = 4 x 2 = 8 cm2

STEP3:

Add the area of both smaller figures.Area of the shaded portion

= 18 cm2 + 8 cm2

= 36 cm2

CONFIDENTIAL 16

BREAK

CONFIDENTIAL 17

Title: Format: WebEx Web BrowserDouble-click to edit

CONFIDENTIAL 18

Assignment

Find the perimeter of the given figures:

2 cm

2 cm

1 cm

1 cm

1 cm

1)

2)

2 cm

4 cm

3)

1 cm4)

CONFIDENTIAL 19

Find the area of the given figures:

2 cm

2 cm

5) 2 cm

4 cm

6)

5 cm

5 cm

7) 3 cm

7 cm

8)

CONFIDENTIAL 20

Find the perimeter of the green portion:

9)

10)

1 cm

1 cm

CONFIDENTIAL 21

Very Good!Let's Review

PERIMETER: It is the distance around a figure.

Area and perimeter are geometric measurements used to measure plane figures.

The perimeter

of the triangle is

3 cms.

1 cm

1 cm

1 cm

CONFIDENTIAL 22

Review

AREA: is the number of square units needed to cover a plane figure.

2 cm

2 cm

The area of the square is 4 cms2.

Use a formula

Area of the square= side x side = 2cm x 2cm=.4 square centimeters

(cm2)

CONFIDENTIAL 23

ReviewPERIMETER: is computed by adding the

lengths of the figure's sides.

For example:We see a hexagon.

2 cm

3 c

m3 c

m

We are supposed to find the perimeter of the hexagon.

CONFIDENTIAL 24

Review

2 cm

3 c

m3 c

m

Add the lengths of the hexagon's sides.

Perimeter (P)

= 2 cm + 3 cm + 3 cm + 2 cm + 3 cm + 3 cm

= 16 cm

The perimeter of the given hexagon is 16 cm.

CONFIDENTIAL 25

Review

AREA: is computed by counting the number of square units or use a formula.

Counting the squares

1 cm

1 cm

Count the number of shaded centimeter squares. There are 6 square centimeters (cm2).

Use a formula

Multiply the length times the width to find the area. Area of the rectangle

= length x width= 2cm x 3 cm=.6 square centimeters (cm2)

CONFIDENTIAL 26

You have done a nice job.See you in the next session.