R/12
04/10/2021, 05/10/2021, 06/10/2021, 07/10/2021, 08/10/2021, 09/10/2021
LINKS
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REVISION
TOPIC: Introduction, Sides, Angles and Diagonals of a Quadrilateral, Adjacent Sides and Opposite Sides, Angle Sum Property of a Quadrilateral, interior and Exterior Angles of a quadrilateral, Exterior Angles Sum property.
EXPLAINED
1. Introduction, Sides, Angles and Diagonals of a Quadrilateral,
2. Adjacent Sides and Opposite Sides,
3. Angle Sum Property of a Quadrilateral,
4. Interior and Exterior Angles of a quadrilateral,
5. Exterior Angles Sum property.
MAIN TEACHING
Oral and explanation with some written work
1. Introduction, Sides, Angles and Diagonals of a Quadrilateral,
2. Adjacent Sides and Opposite Sides,
3. Angle Sum Property of a Quadrilateral,
4. Interior and Exterior Angles of a quadrilateral,
5. Exterior Angles Sum property.
WATCH THE VIDEOS FOR YOUR BETTER UNDERSTANDING
STUDENTS TAKE AWAY
Complete all examples and Exercise 12 from given link of chapter.
ASSIGNMENT
Complete the questions given in Chapter Assessment in OCB
R/11
24/09/2021, 25/09/2021, 27/09/2021, 28/09/2021, 29/09/2021, 30/09/2021, 01/10/2021
LINKS
Click on the chapter's name to download the chapter in PDF form.
REVISION
TOPIC: Introduction, Review of concepts and Definitions, Classification of polynomials, Addition of algebraic expressions, Subtraction of algebraic expressions, Multiplication of algebraic expressions, Division of algebraic expressions, Special products of Binomials (IDENTITIES).
EXPLAINED
1. Introduction
2. Review of concepts and Definitions
2.1 Constant: A symbol having a fixed numerical value is called a constant.
2.2 Variable: A symbol which takes various numerical values is called a variable.
2.3 Algebraic Expressions: A combination of constants and variables connected by the signs of fundamental operations of addition (+), subtraction (-), multiplication (×), and division ( ÷) is called an algebraic expression.
2.4 Terms: Various parts of an algebraic expression which are separated by the signs of ‘+’ or ‘ ─’ are called the terms of the expression
2.5 Like Terms: The terms having the same literal factors are called like or similar.
2.6 Unlike terms: The terms not having same literal factors are called unlike or dissimilar terms
2.7 Coefficients: In a term of an algebraic expression, any of the factors with the signs of the term is called the coefficient of the product of the other factors.
2.8 Polynomials: An algebraic expression containing two or more terms is called a polynomial. x +3, 2x – y + 3, 4x3 – x2 + 6x +3, 7y3 + 5y2 – 8y +9.
3. Classification of polynomials
3.1 Monomial: An algebraic expression containing only one term is called a monomial. Example:- 3, 2x, 5x2y, -6abc, 3ab2c3
3.2 Binomial: An algebraic expression containing two terms is called a binomial. Example:- x +3, 5 – 2x, a2 – 2abc, x3 + 3
3.3 Trinomial: An algebraic expression containing three terms is called a trinomial. Example:- 2x – y + 3, x2 + y2 + z2, 3 + xyz + x3.
4. Addition of algebraic expressions
5. Subtraction of algebraic expressions
6. Multiplication of algebraic expressions
7. Division of algebraic expressions
8. Special products of Binomials (IDENTITIES).
MUST WATCH VIDEO FOR BETTER UNDERSTANDING
1. Introduction (Algebraic Expression)
2. Parts of an Algebraic expression: Factors
3. Parts of an Algebraic expression: Coefficients
4. Like and Unlike terms
5. Types of Algebraic Expressions
6. Addition of algebraic expressions
7. Subtraction of algebraic expressions
8. Multiplication of algebraic expressions
9. . Special products of Binomials (IDENTITIES)
MAIN TEACHING
Oral and Explanation Online with some written work.
1. Introduction
2. What are Expressions?
3. Monomials, Binomials and Polynomials
4. Addition and Subtraction of algebraic expressions
5. Multiplication of algebraic expressions and Identity
STUDENTS TAKE AWAY
Complete all questions of Exercise 5(A), 5(B), 5(C), 5(D), 5(E), 5(F), 5(G), and 5(H) from given link of chapter.
ASSIGNMENT
Complete the questions given in Mental Maths and Multiple Choice Questions in OCB.
R/10
13/09/2021, 14/09/2021, 20/09/2021, 21/09/2021
LINKS
Click on the chapter’s name to download the chapter in PDF form.
CH-14 PROBABILITY TOPIC: Introduction, Conditional Probability, Multiplication Theorem on Probability, Independent Events, Baye’s Theorem, Random variables and its Probability, Distributions, Bernoulli Trials and Binomial Distribution.
EXPLAINED
1. Introduction (Probability)
1.1 Probability: Probability is a branch of mathematics that deals with calculating the likelihood of a given event’s occurrence.
2. Some terms related to Probability
2.1 Experiment: An operation which can produce some well-defined outcomes, is called an experiment.
2.2 Random Experiment: An experiment in which all possible outcomes are known and the exact outcome cannot be predicted in advance, is called a random experiment.
2.3 Trial: By a trial, we mean performing a random experiment.
2.4 Event: Outcome associated with an experiment is called an event.
2.5 Sure events: The events whose probability is one are called sure events.
2.6 Impossible events: The events whose probability is zero are called impossible events.
2.7 Elementary event: An event with only one possible outcome is called an elementary event.
3. Probability of an event E, denoted as P(E), is given by
MUST WATCH THE VIDEO FOR BETTER UNDERSTANDING
1. Probability
1. Definition of Probability
STUDENTS TAKE AWAY
Complete all questions of Exercise- 14 from given link of chapter.
ASSIGNMENT
Complete the questions given in Mental Maths and Multiple Choice Questions in OCB.
R/9
31/08/21, 03/09/21, 06/09/21, 07/09/21, 10/09/21
LINKSClick on the chapter’s name to download the chapter in PDF form.
TOPIC: Introduction, A review of work done earlier, Finding a Percentage of a number, Percent Increase and Decrease, Profit and Loss, Simple Interest, Compound Interest, Discount
EXPLAINED
1. Introduction (Percentage)
Percent: The word percent is an abbreviation of the Latin phrase ‘per centum’ which means per hundred or hundredths. The Symbol % is used for the term percent.
2. A review of work done earlier
2.1 Ratio
2.2 Proportion
2.3 Percent as a Ratio
2.4 Percent in Decimal Form
3. Finding a Percentage of a Number
To find a percent of a given number, we proceed as follows:
Step I: Obtain the number, say x.
Step II: Obtain the required percent, say P %.
Step III: Multiply x by P and divide by 100 to obtain the required P % of x
i.e. P % of x = P/100 × x
Example: Find: (i) 12% of Rs 1200
Solution: 12% of Rs 1200 = Rs 12/100 × 1200
= 144
4. Percent Increase and Decrease
5. Discount
6. Review of Concepts
6.1 Cost Price: The amount paid to purchase an article or the price at which an article is made is known as its cost price.
The cost price is abbreviated as C.P.
6.2 Selling Price: The price at which an article is sold is known as its selling price. The selling price is abbreviated as S.P.
6.3 Profit: If the selling price (S.P.) of an article is greater than the cost price (C.P.), the difference between the selling price and cost price is called profit.
Thus, if S.P. > C.P., then
Profit = S.P. – C.P.
6.4 Profit Percentage: The profit percent is the profit that would be obtained for a C.P. of Rs 100 i.e.,
6.5 Loss: If the selling price (S.P.) of an article is less than the cost price (C.P.), the difference between the cost price (C.P.) and the selling price (S.P.) is called loss.
Thus, if S.P. < C.P., then
Loss = C.P. – S.P.
6.6 Loss Percentage: The loss percent is the loss that would be made for a C.P. of Rs 100. i.e.,
7. Simple Interest
8. Compound Interest
MUST WATCH VIDEO FOR BETTER UNDERSTANDING
1. Introduction
2. Ratio
3. Convert Ratio to Percentages
4. Convert Decimal number into Percentage
5. Profit and Loss Percentage
6. Simple Interest
7. Compound Interest
8. Use of Compound Interest Formula
MAIN TEACHING
Online oral explanation and some written work
1. What is Percentage?
2. Ratio
3. Definition
4. Formulae
5. Compound Interest
STUDENTS TAKE AWAY
Complete all questions of Exercise 8(A), 8(B), 8(C), 8(D) and 8(E) from given link of chapter.
ASSIGNMENT
Complete the questions given in Mental Maths and Multiple Choice Questions in OCB.
R/8
23/08/21, 24/08/21, 27/08/21
CONTINUATION OF CH:- 12
LINKS
Click on the chapter’s name to download the chapter in PDF form.
TOPIC: Volume of a Cuboid and a Cube, Volume of a Cylinder.
EXPLAINED
2.3 Cylinder
2.4 Cone
2.5 Sphere
6. Volume and surface area of a Cylinder
Let us consider a cylinder whose height is h units and the radius of whose base is r units. Then we have
6.1 Volume of the cylinder = (pr2h) cubic units.
6.2 Curved surface area of the cylinder = (2prh) sq units.
6.3 Total surface area of the cylinder = 2pr( h + r) sq units.
Example:
~ Find the volume, curved surface area, and total surface area of a cylinder having radius of the base 14 cm and height 30 cm.
Solution: Here, r = 14 cm and h = 30 cm.
(i) Volume of the cylinder = (pr2h) cubic units
= (22/7 x 14 x 14 x 30) cm3
= 18480 cm3.
(ii) Curved surface area of the cylinder = (2prh) sq units
= (2 x 22/7 x 14 x 30) cm2
= 2640 cm2.
(iii) Total surface area of the cylinder = 2pr( h + r) sq units
= [2 x 22/7 x 14 x ( 14 + 30)] cm2
= 3872 cm2.
MUST WATCH VIDEO FOR BETTER UNDERSTANDING
1. Surface area of a Cylinder
2. Volume of a cube
3. Volume of Cuboid and Cylinder
MAIN TEACHING
Online oral explanation and some written work
1. What is Mensuration?
2. Area and Perimeter of 2-D figures
3. Volume, Total surface area and Curved surface area of 3-D Figures
STUDENTS TAKE AWAY
Complete all questions of Exercise 12(E) and 12(F) from given link of chapter.
ASSIGNMENT
I. Complete the questions given in Mental Maths and Multiple Choice Questions in OCB.
R/7
02/08/21, 03/08/21, 06/08/21, 10/08/21
LINKS
Click on the chapter’s name to download the chapter in PDF form.
TOPIC: Introduction, Area of Plane Shapes, Area of Trapezium, Area of a Polygon, Surface Area of a Cuboid, Surface Area of a Cube, Cylinder, Area of curved surface of Cylinder, Volume of a Cuboid and a Cube, Volume of a Cylinder.
EXPLAINED
1. Introduction (Mensuration)
The word “Mensuration” is derived from the Greek word “Mensuration” meaning “to measure” and refers to that branch of mathematics and deals with the measurement of geometric magnitudes, such as areas of surfaces and volumes of solids. It is a practical branch of mathematics.
It is categorized in two parts:
1. Mensuration of 2-D figures
Some of 2-D shapes in mensuration
1.1 Square
1.2 Rectangle
1.3 Parallelogram
1.4 Rhombus
1.5 Triangle
1.6 Trapezoid
1.7 Circle
2. Mensuration of 3-D figures
Some of 3-D shapes in Mensuration
2.1 Cuboid
2.2 Cube
2.3 Cylinder
2.4 Cone
2.5 Sphere
3. Introduction (TSA, LSA and Volume)
3.1 Total Surface Area (TSA): Total surface area is the sum of the areas of all the sides of three dimensional figure.
3.2 Lateral surface area (LSA): Lateral surface area is the sum of the areas of all sides of a 3D object except its top and bottom bases.
3.3 Volume: The space occupied by a solid body is called its volume.
4. Area of a Trapezium
Area of Trapezium = ½ x (Sum of the parallel sides) x (Distance between parallel sides)
= ½ x ( a + b) x h sq units.
Example:
~ Find the area of a trapezium whose parallel sides are of lengths 10 cm and 12 cm and the distance between them is 4 cm.
Solution: Here, Sum of the parallel sides (a = 10 cm, b = 12 cm). Distance between parallel sides (h) = 4 cm.
Area of the trapezium = ½ x ( a + b) x h sq units
= [½ x (10 + 12) x 4] cm2
= [½ x 22 x 4] cm2
= 44 cm2.
4. Volume and Surface Area of a Cuboid
Formulae:
Let us consider a Cuboid of length = l units, breadth = b units, and height =h units. Then, we have
4.1 Total surface area of the Cuboid = 2(lb + bh + lh) sq units.
4.2 Lateral surface area of the Cuboid = [2(l + b) x h] sq units.
4.3 Volume of the Cuboid = (l x b x h) cubic units.
Example:
~ Find the volume, the total surface area and the lateral surface area of a Cuboid
which is 15 m long, 12 m wide and 4.5 m high.
Solution:
Here, l = 15 m, b = 12 m and h = 4.5 m
Volume of the Cuboid = (l x b x h) cu units.
= (15 x 12 x 4.5) m3
= 810 m3
Total surface area of the Cuboid = 2(lb + bh + lh) sq units
= 2(15 x 12 + 12 x 4.5 + 15 x 4.5) m2
= 603 m2.
Lateral surface area of the Cuboid = [2(l + b) x h] sq units
= [2(15 + 12) x 4.5] m2
= 243 m3.
5. Volume and Surface Area of a Cube
Formulae:
Let us consider a cube of edge = a units. Then we have
5.1 Volume of the cube = a3 cubic units.
5.2 Total surface area of the cube = 6a2 sq units.
5.3 Lateral surface area of the cube = 4a2 sq units.
Example:
~ Find the volume, total surface area and lateral surface area of a cube, each of
whose edges measures 20 cm.
Solution: Here, a = 20 cm.
Volume of the cube = a3 cubic units
= (20 x 20 x 20) cm3
= 8000 cm3.
Total surface area of the cube = 6a2 sq units
= (6 x 20 x 20) cm2
= 2400 cm2.
Lateral surface area of the cube = 4a2 sq units
= (4 x 20 x 20) cm2
= 1600 cm2.
6. Volume and surface area of a Cylinder
Formulae:
Let us consider a cylinder whose height is h units and the radius of whose base is r units. Then we have
6.1 Volume of the cylinder = (pr2h) cubic units.
6.2 Curved surface area of the cylinder = (2prh) sq units.
6.3 Total surface area of the cylinder = 2pr( h + r) sq units.
Example:
~ Find the volume, curved surface area, and total surface area of a cylinder
having radius of the base 14 cm and height 30 cm.
Solution: Here, r = 14 cm and h = 30 cm.
(i) Volume of the cylinder = (pr2h) cubic units
= (22/7 x 14 x 14 x 30) cm3
= 18480 cm3.
(ii) Curved surface area of the cylinder = (2prh) sq units
= (2 x 22/7 x 14 x 30) cm2
= 2640 cm2.
(iii) Total surface area of the cylinder = 2pr( h + r) sq units
= [2 x 22/7 x 14 x ( 14 + 30)] cm2
= 3872 cm2.
MUST WATCH THE VIDEOS FOR BETTER UNDERSTANDING
1. Introduction (Area of Plane Shapes)
2. Area of Trapezium
3. Area of a Polygon
4. Surface Area of a Cuboid, and a Cube
5. Surface area of a Cylinder
6. Volume of a cube
7. Volume of Cuboid and Cylinder
MAIN TEACHING
Online oral explanation and some written work
1. What is Mensuration?
2. Area and Perimeter of 2-D figures
3. Volume, Total surface area and Curved surface area of 3-D Figures
STUDENTS TAKE AWAY
Complete all questions of Exercise 12(A), 12(B), 12(C), 12(D), 12(E) and 12(F) from given link of chapter.
ASSIGNMENT
I. Complete the questions given in Mental Maths and Multiple Choice Questions in OCB.
II. Choose the correct alternative in each of the following:
1. The formula for lateral surface area of Cuboid is
(a) 2h (l + b) (b) 2l (h + b) (c) 2b(l + h) (d) 2(lb + bh + hl)
2. The cost of papering the wall of a room, 12m long, at the rate of Rs.1.35 per square meter is Rs.340.20. The cost of matting the floor at Re.0.85 per square meter is Rs.91.80. Find the height of the room.
(a) 12m (b) 8m (c) 6m (d) 10m
3. The length of parallel sides of trapezium is 14cm and 6cm and its height is 5cm. Its area will be
(a) 50cm2 (b) 100cm2 (c) 210cm2 (d) 10cm2
4. Two dimensional figure is a
(a) solid figure (b) plane figure (c) cylinder figure (d) None of these
5. Surface area of a Cuboid = ___________.
(a) 2h (l + b) (b) 2lbh (c) 2 (lb + bh + hl)) (d) None of these
6. A rectangular paper of width 7cm is rolled along its width and a cylinder of radius 20cm is formed. Find the volume of the cylinder.
(a) 8800cm3 (b) 8800cm (c) 8800cm2 (d) None of these
7. The formula for finding lateral surface area of cylinder is
(a) 2prh (b) ) pr2 (c) ) 2pr(r + h) (d) ) 2pr
8. Which of the following is an example of two dimensions?
(a) Cuboid (b) ) cone (c) ) sphere (d) ) circle
9. Find the volume of a Cuboid whose length = 8cm, breadth= 6cm and height = 3.5cm.
(a) 168cm2 (b) 168cm3 (c) 215cm3 (d) 150cm3
10. In a quadrilateral, half of the product of the sum of the lengths of parallel sides and the parallel distance between them gives the area of
(a) rectangle (b) parallelogram (c) triangle (d) trapezium
11. Diagonals of rhombus are
(a) equal (b) half of one diagonal
(c) different length (d) none of above
12. The area of four walls of the room is
(a) 2(lb + bh + hl))) (b) 2l (h + b)
(c) 2(lb x bh x hl)) (d) 2h (l + b)
13. Find the height of Cuboid whose volume is 490cm3 and base area is 35cm2.
(a) 12cm (b) 14cm (c) 10cm (d) 16cm
14. The amount of space occupied by a three dimensional objects is called its
(a) area (b) surface area
(c) volume (d) lateral surface area
15. A cylindrical tank has a capacity of 5632m3, if the diameter of its base is 16m, find its depth.
(a) 66m (b) 30m (c) 26m (d) 28m
16. Find the total surface area of a cube whose volume is 343cm3.
(a) 350cm2 (b) 294cm2 (c) 494cm2 (d) 200cm2
17. Solid figures are
(a) 2D (b) 3D (c) 1D (d) 4D
18. The area of a trapezium is
(a) ½ (sum of parallel sides) x h (b) 2 (sum of parallel sides) x h
(c) (sum of parallel sides) x h (d) ½ (sum of parallel sides) + h
19. The formula for finding total surface area of Cuboid is
(a) 2(lb x bh x hl))) (b) 2(lb + bh + hl)
(c) 2lb (bh + hl) (d) 2h (l + b)
20. Find the volume of a Cuboid whose length is 8cm, breadth 6cm and height 3.5cm.
(a) 215cm3 (b) 168cm3 (c) 172cm3 (d) 150cm3