Showing posts with label class8-maths. Show all posts
Showing posts with label class8-maths. Show all posts

Thursday 7 September 2017

CBSE Class 8 - Maths - Square and Square Roots - Worksheet (#cbseNotes)

Square and Square Roots - Worksheet

CBSE Class 8 - Maths - Square and Square Roots - Worksheet (#cbseNotes)


Q1. Find the Pythagorean triplets whose one member is:
a) 8      b) 12


Q2. Is 2352 is a perfect square number? If not, find the smallest multiple of 2352 which is a perfect square. Find the square root of the new number.


Q3. Find the smallest square number that is divisible by each of the numbers 8, 15, 20.


Q4. There are 2401 students in a school P.T. teacher wants them to stand in rows and columns such that number of rows is equal to the number of columns. Find the number of rows.


Thursday 24 August 2017

Maths Pearls - What is so special about Srinivasa Ramanujan's Magic Square? (#cbseNotes)

What is so special about Srinivasa Ramanujan's Magic Square?

Maths Pearls - What is so special about Srinivasa Ramanujan's Magic Square? (#cbseNotes)


You may be familiar with magic squares. Srinivasa Ramanujan also designed his own magic square.

Maths Pearls - What is so special about Srinivasa Ramanujan's Magic Square? (#cbseNotes)


This magic square looks similar to any other square. What is so special about it?


Sum of any rows is 139

Maths Pearls - What is so special about Srinivasa Ramanujan's Magic Square? (#cbseNotes)


Sunday 23 July 2017

CBSE Class 8 - Mathematics - Data Handling (Worksheet) (#cbseNotes)

Data Handling (Worksheet) 

CBSE Class 8 - Mathematics - Data Handling (Worksheet)  (#cbseNotes)

Fill in the blanks.

The information collected in term of numbers is called __________.


Data available in an unorganised form are called __________.


The number of times a particular observation occurs in a given data is called its __________.


When the data are large, they can be arranged in groups and each group is known as ___________ or __________.


Tuesday 18 July 2017

CBSE Class 8 - Maths - Periodic Test 1 (2017-18) (#cbseNotes)

CBSE Class 8 - Maths - Periodic Test 1 (2017-18) (#cbseNotes)

CBSE Class 8 - Maths - Periodic Test 1 (2017-18) 

Chapters Covered are:

1. Rational Numbers
2. Quadrilaterals
3. Linear Equations Of One Variable

Tuesday 11 July 2017

CBSE Class 8 - Maths Periodic Assessment-1 (2017-18) (#cbseNotes)

CBSE Class 8 - Maths Periodic Assessment-1 (2017-18) (#cbseNotes)

CBSE Class 8 - Maths Periodic Assessment-1 (2017-18

Questions asked in the Q. Paper are from the following chapters:

1. Rational Numbers


Friday 3 March 2017

CBSE Class 8 - Maths - Squares - Properties of A Perfect Square (#cbsenotes)

Properties of A Perfect Square

CBSE Class 8 - Maths - Squares - Properties of A Perfect Square (#cbsenotes)

Please look at the table of some squares given below. You will see interesting patterns here.

Square of number 0 = 0

Number Square Number Square Number Square
1 1 11 121 21 441
2 4 12 144 22 484
3 9 13 169 23 529
4 16 14 196 24 576
5 25 15 225 25 625
6 36 16 256 26 676
7 49 17 289 27 729
8 64 18 324 28 784
9 81 19 361 29 841
10 100 20 400 30 900


PROPERTY 1:
Look at the table above. Observe that none of the column of squares ends with 2, 3, 7, or 8. Therefore we can say that a number endings with 2, 3, 7, 8 can never be a perfect square.
Thus 228257 , 132457 , 189678 , 84453 are not perfect squares.

PROPERTY 2:
Look at the last row of the table shown above. We notice that all the perfect squares are ending with an even number or 0. In the first line  e.g. 10² = 100 , 20² = 400, 30² =900,
Similarly 80²  = 6400, 50² = 2500.

We can prime factorise and see that 10, 20, 30,  etc . are not perfect squares. Thus a number ending with odd  number of zeros can never be a perfect square.


Friday 17 February 2017

CBSE Class 8 - Maths - CH3 - Understanding Quadrilaterals (Worksheet) (#cbsenotes)

Understanding Quadrilaterals

CBSE Class 8 - Maths - CH3 - Understanding Quadrilaterals (Worksheet) (#cbsenotes)
(Worksheet)

The worksheet helps you identify a specific quadrilateral based on its properties.

☛Directions: Fill in the blanks

A simple closed curve made up of only line segments is called a ________.
 


A _________ of a polygon is a line segment connecting two non- consecutive vertices.
 


A _______ _______ is a polygon in which no portion of its any diagonal is in its exterior.
 


A quadrilateral is a polygon having only ________ sides.
 

Thursday 5 January 2017

Class 8/ Class 9 - Properties Of Quadrilateral Figures (Worksheet) (#CBSEClass8Maths) (#CBSEClass9Maths)

Properties Of Quadrilateral Figures

Class 8/ Class 9 - Properties Of Quadrilateral Figures (Worksheet) (#CBSEClass8Maths) (#CBSEClass9Maths)

(Worksheet)

Question. Fill in the blanks (True or False) for the properties of the following figures:


Property Parallelogram Rhombus Rectangle Square
1. Both pairs of opposite sides are parallel and equal. ? ? ? ?
2. Both pairs of opposite angles are equal. ? ? ? ?
3. Diagonals bisect each other. ? ? ? ?
4. Diagonals are equal. ? ? ? ?
5. Each angle is 90° ? ? ? ?
6. Diagonals intersect at right angles. ? ? ? ?
7. All sides are equal. ? ? ? ?


Wednesday 4 January 2017

CBSE Class 8 - Maths - Comparing Quantities (Worksheet) (#CBSENotes)

Comparing Quantities

CBSE Class 8 - Maths - Comparing Quantities (Worksheet) (#CBSENotes)

Worksheet

Class 8  NCERT Exemplar Chapter Answers

In the following questions, fill in the blanks to make the statements true.

1. _________ is a reduction on the marked price of the article.

2. Increase of a number from 150 to 162 is equal to increase of _________ per cent.

3. 15% increase in price of an article, which is Rs 1,620, is the increase of Rs _________.

4. Discount = _________ – _________.

5. Discount = Discount % of _________.

6. _________ is charged on the sale of an item by the government and is added to the bill amount.

Saturday 31 December 2016

CBSE Class 8 - Mathematics - Direct and Inverse Proportions

Direct and Inverse Proportions
CBSE Class 8 - Mathematics
CBSE Class 8 - Mathematics - Direct and Inverse Proportions

NCERT Exemplar Problems and Solutions


Q1: If x and y are directly proportional and when x = 13, y = 39, which of the following is not a possible pair of corresponding values of x and y ?

(a) 1 and 3
(b) 17 and 51
(c) 30 and 10
(d) 6 and 18

Answer: (c) 30 and 10
For direct variation,
x1   =  x2
y1 y2

Thus x/y = 13/39 = 1/3. Options (a), (b) and (d) have the same ratio while option (c) does not.


Q2: Which of the following is in direct proportion?

(a) One side of a cuboid and its volume.
(b) Speed of a vehicle and the distance travelled in a fixed time interval.
(c) Change in weight and height among individuals.
(d) Number of pipes to fill a tank and the time required to fill the same tank.

Answer: (b) Speed of a vehicle and the distance travelled in a fixed time interval.
∵ Speed / distance = fixed ratio.


Q3: Both u and v vary directly with each other. When u is 10, v is 15, which of the following is not a possible pair of corresponding values of u and v?

(a) 2 and 3
(b) 8 and 12
(c) 15 and 20
(d) 25 and 37.5


Answer: (c) 15 and 20
u/v = 2/3
Option (C) does not maintain the same ratio.

Wednesday 21 December 2016

Class 8 Mathematics - Rotational Symmetry

Rotational Symmetry

Swastika has a rotational symmetry (order:4)
image credits: wikipedia

Class 8 Mathematics 

A figure has rotational symmetry if the object can be rotated about a fixed point without changing the overall shape.

e.g. Consider the following equilateral triangle, if you rotate by 120°, you get the same figure.
Order of Rotational Symmetry
The order of rotational symmetry is the number of times the shape maps onto itself during a rotation of 360°.

Saturday 3 December 2016

CBSE Class 8 Maths - Linear Equations In One Variable (Q and A) (#eduvictors)(#class8Maths)

Linear Equations In One Variable

Class 8 Maths

Q & A based on Class 8 NCERT Chapter 

CBSE Class 8 Maths - Linear Equations In One Variable (Q and A)


Q1(MCQ): If 3x – 4 (64 – x) = 10, then the value of x is

(a) –266
(b) 133
(c) 66.5
(d) 38



Answer: (d)38
  3x - 256 + 4x =10
  7x = 10 + 256 = 266
  x = 266/7 = 38


Q2: Three consecutive even numbers whose sum is 156 are 51, 52 and 53.
State if the above statement is True or False

Answer: False

Let the three consecutive even numbers be x, x+2, x+4
∴ x + x+ 2 + x+4 = 156
⇒ 3x + 6 = 156
⇒ 3x = 156 - 6 = 150
⇒ x = 150 /  3 = 50
Thus numbers are 50, 51, 52


Q3: Fifteen added to thrice a whole number gives 93. The number is __________.

Answer: 26



Q4: x = –12 is the solution of the linear equation 5x –3(2x + 1) = 21+x (True or False)


Wednesday 9 November 2016

CBSE Class 8 - Mathematics - Factorisation - NCERT Exercise (14.2)

Factorisation

CBSE Class 8 - Mathematics - Factorisation - NCERT Exercise (14.2)

NCERT Exercise 14.2



Q1: Factorise the following expressions.

(i) a2 + 8a + 16

(ii) p2 − 10p + 25

(iii) 25m2 + 30m + 9

(iv) 49y2 + 84yz + 36z2

(v) 4x2 − 8x + 4

(vi) 121b2 − 88bc + 16c2

(vii) (l + m)2 − 4lm (Hint: Expand (l + m)2 first)

(viii) a4 + 2a2b2 + b4



Answer:

(i) a2 + 8a + 16 = (a)2 + 2 ☓ a ☓ 4 + (4)2

= (a + 4)2 [(x + y)2 = x2 + 2xy + y2]


(ii) p2 − 10p + 25 = (p)2 − 2 ☓ p ☓ 5 + (5)2

= (p − 5)2 [(a − b)2 = a2 − 2ab + b2]


(iii) 25m2 + 30m + 9 = (5m)2 + 2 ☓ 5m ☓ 3 + (3)2

= (5m + 3)2 [(a + b)2 = a2 + 2ab + b2]

(iv) 49y2 + 84yz + 36z2 = (7y)2 + 2 ☓ (7y) ☓ (6z) + (6z)2

= (7y + 6z)2 [(a + b)2 = a2 + 2ab + b2]

(v) 4x2 − 8x + 4 = (2x)2 − 2 (2x) (2) + (2)2

= (2x − 2)2 [(a − b)2 = a2 − 2ab + b2]

= [(2) (x − 1)]2 = 4(x − 1)2

(vi) 121b2 − 88bc + 16c2 = (11b)2 − 2 (11b) (4c) + (4c)2

= (11b − 4c)2 [(a − b)2 = a2 − 2ab + b2]

(vii) (l + m)2 − 4lm = l2 + 2lm + m2 − 4lm

= l2 − 2lm + m2

= (l − m)2 [(a − b)2 = a2 − 2ab + b2]

(viii) a4 + 2a2b2 + b4 = (a2)2 + 2 (a2) (b2) + (b2)2

= (a2 + b2)2 [(a + b)2 = a2 + 2ab + b2]


Saturday 5 November 2016

CBSE Class8 - Mathematics - Ch 14 - Factorisation (NCERT Ex 14.1)

Factorisation

NCERT Exercise 14.1 Solutions

CBSE Class8 - Mathematics - Ch 14 - Factorisation (NCERT Ex 14.1)


Q1: Find the common factors of the terms

(i)   12x, 36

(ii)  2y, 22xy

(iii)  14pq, 28p2q2

(iv) 2x, 3x2, 4

(v) 6abc, 24ab2, 12a2b

(vi) 16x3, −4x2, 32x

(vii) 10pq, 20qr, 30rp

(viii) 3x2y3, 10x3y2, 6x2y2z

Answer:

(i) 12x = 2 ☓ 2 ☓ 3 ☓ x

36 = 2 ☓ 2 ☓ 3 ☓ 3

The common factors are 2, 2, 3.

And, 2 ☓ 2 ☓ 3 = 12

(ii) 2y = 2 ☓ y

22xy = 2 ☓ 11 ☓ x ☓ y

The common factors are 2, y.

And, 2 ☓ y = 2y

(iii) 14pq = 2 ☓ 7 ☓ p ☓ q

28p2q2 = 2 ☓ 2 ☓ 7 ☓ p ☓ p ☓ q ☓ q

The common factors are 2, 7, p, q.

And, 2 ☓ 7 ☓ p ☓ q = 14pq

(iv) 2x = 2 ☓ x

3x2 = 3 ☓ x ☓ x

4 = 2 ☓ 2

The common factor is 1.

Monday 10 October 2016

CBSE - Class 6-12 - Mathematics - Important Formulas

Mathematics - Important  Formulas 



eduvictors.com has added a new section "Mathematics" and has compiled important formulas on different topics.

Here is the list of Mathematics formulas:

1. Algebra Formulas

⓵ Polynomials
⓶ Fractions
⓷ Algebraic Identities
⓸ Exponents
⓹ Roots