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)

CONFIDENTIAL3 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

CONFIDENTIAL4 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.

CONFIDENTIAL5 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 = __ grams 5,000 ÷ 1000 = 5 5,000 milligrams = 5 grams 5,000 milligrams is equal to 5 grams.

CONFIDENTIAL6 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.

CONFIDENTIAL7 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 = __ kilograms 5,000 ÷ 1000 = 5 5,000 grams = kilograms 5,000 grams is equal to 5 kilograms.

CONFIDENTIAL8 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

CONFIDENTIAL9 AREA: is the number of square units needed to cover a plane figure. 2 cm The area of the square is 4 cms 2. Use a formula  Area of the square = side x side = 2cm x 2cm =.4 square centimeters (cm 2 )

CONFIDENTIAL10 PERIMETER: is computed by adding the lengths of the figure's sides. For example: We see a hexagon. 2 cm 3 cm We are supposed to find the perimeter of the hexagon.

CONFIDENTIAL11 2 cm 3 cm 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.

CONFIDENTIAL12 AREA: is computed by counting the number of square units or use a formula. Counting the squares 1 cm  Count the number of shaded centimeter squares.  There are 6 square centimeters (cm 2 ).

CONFIDENTIAL13 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 (cm 2 )

CONFIDENTIAL14 Area of a complex figure Find the area of the green portion 1 cm STEP1: Divide the figure into rectangle or square.

CONFIDENTIAL15 STEP2: Find the area of each smaller figure. Area of green rectangle = 3 x 6 = 18 cm 2 Area of blue rectangle = 4 x 2 = 8 cm2 STEP3: Add the area of both smaller figures. Area of the shaded portion = 18 cm cm 2 = 36 cm 2

CONFIDENTIAL16 BREAK

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CONFIDENTIAL18 Assignment Find the perimeter of the given figures: 2 cm 1 cm 1) 2) 2 cm 4 cm 3) 1 cm 4)

CONFIDENTIAL19 Find the area of the given figures: 2 cm 5) 2 cm 4 cm 6) 5 cm 7) 3 cm 7 cm 8)

CONFIDENTIAL20 Find the perimeter of the green portion: 9) 10) 1 cm

CONFIDENTIAL21 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

CONFIDENTIAL22 Review AREA: is the number of square units needed to cover a plane figure. 2 cm The area of the square is 4 cms 2. Use a formula  Area of the square = side x side = 2cm x 2cm =.4 square centimeters (cm 2 )

CONFIDENTIAL23 Review PERIMETER: is computed by adding the lengths of the figure's sides. For example: We see a hexagon. 2 cm 3 cm We are supposed to find the perimeter of the hexagon.

CONFIDENTIAL24 Review 2 cm 3 cm 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.

CONFIDENTIAL25 Review AREA: is computed by counting the number of square units or use a formula. Counting the squares 1 cm  Count the number of shaded centimeter squares.  There are 6 square centimeters (cm 2 ). 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 (cm 2 )

CONFIDENTIAL26 You have done a nice job. See you in the next session.