Lesson 90:
Finding the volume of a given cube and rectangular prism using cu.cm and cu.m
1.Drill
Mental computation /drill on finding the area or missing side of a parallelogram
Review
Find the area of the following figures. Write the answer on your notebook.
3 cm
5 cm
5 cm
6 cm
.Motivation
Show a transparent plastic container filled with balls. Ask pupils to guess the number of balls inside the container. Let a volunteer count the balls to find out the answer. Elicit from them how they can make a good guess of the total number of balls. Relate this to the concept of volume.
Presentation
Read and study the problem below.
A storage box is 60 cm by 40 cm by 30 cm. What is the volume of the box?
The volume of a rectangular prism is equal to the product of its length, width and height.
V= LXWXH 60cm x 40 cm x 30 cm = 72000cm3
Using concrete objects
a.Let a pupil fill a rectangular box with cubes.
b.Ask the pupils the following questions:
How many cubes did it take to fill the prism?
How many cubic units is the length/ the width? the height?
c.Define these situations as finding the volume of solids. Define volume as the number of cubic units used to fill up a space. Use correct unit of measure.
d.Using this definition, ask the pupils the volume of rectangular prism.
e.Let them state the formula for the volume of a rectangular prism as V=lxwxh
Performing the Activities
Solve for the volume of these rectangular prisms, given their measurements.
1.l=9m
w=4m
h=3m
2.l= 10cm
w=7cm
h=15cm
3. s=12cm
4. l=14 m
w=10m
h=9m
5. s=6m
Processing the Activities
What is volume?
What is the formula in finding the volume of a cube? Rectangular prism
Find the volume of each prism.
1. l=4m
w=2.5m
h=-3.5m
V= _____
2. l=8cm
w=4cm
h=5cm
V= _____
Solve the following word problems.
Summarizing the Lesson
Volume of a rectangular prism= L X W X H
Volume of a cube=S X S X S or S3
Find the volume of the following figures.
12 cm
8 cm
5 cm
10 cm
Draw the figure with their measurements and find their volume.
1. l=4m
w=1m
h=3m
2.s=14cm
3.3=20cm
4.l=8cm
w=3cm
h=10cm
5.s=12cm
Day 4
1.Drill
Mental computation
Magic Square –Give the next five perfect square.
Review
Find the volume of these prisms. Write the answer on your notebook.
1.l=9m
w=5m
h=4m
2. s=12cm
3.l=15m
w=10m
h=6m
Presentation
Using concrete object (present an aquarium)
An aquarium is 35 cm. long, 25 cm wide and 33 cm high is to be filled with water.
How many cubic centimetre of water will be needed?
1.What is asked in the problem?
2.What data are given?
3. Is the unit of measure appropriate with the data given?
2.Performing the Activities
a. Group the pupils. Give rectangular prism to each group.
b. Have each pupil first guess which prism has the greatest and which prism has the least volume.
c. Give the unit of measure to be used. Have the students estimate the volume of the rectangular prisms.
. Processing the Activities
What is volume?
How do we estimate volume of a prism?
Have the pupils solve the following exercises.
Write the best unit of measure to find the volume of the following: (mm3, cm3, dm3, m3)
1.water in a rectangular pool
2.an ice before it melts
3.a dice
4.a blackboard eraser
5.oil in a rectangular box
Solve the following word problems.
1.The volume of a rectangular prism is 240 cm3.Its length is 4cm and its height is 6 cm. How wide is it?
Summarizing the Lesson
How do we use appropriate unit of measure for volume?
How do we estimate volume?
.Assessment
1.Marilou’s sewing box is 3 dm long, 2.5 dm wide and 4.3 dm high. What is its volume?
2.Find the volume of a closet which is 2.5 m long, 5m and 2m high
Draw the figure with their measurements and find their volume.
1. l=9m
w=4m
h=6m
2. s=18cm
.3. 3=30cm
4. l=12cm
w=5cm
h=8cm
5. s=14cm
DAY 5
WEEKLY TEST