Knowing Our Numbers
Q 1) Fill in the blanks.
i)CXXXI is written in Hindu-Arabic numeral as …………..
ii)Quotient obtained on dividing successor of the greatest 5-digit number by the lowest 6-digit number is ………….
iii)One billion is equal to …………………. Million.
iv)The number 764837 rounded off to ten thousands place is ……………..
v)Estimated product of 4075 X 206 is …………..
Q 2) True or False.
i)Eighty four in Roman numeral is written as CXXXIV.
ii)There are seven zeroes in 1 crore.
iii)There are ten lakh milligrams in 1 kg.
iv)The smallest 4-digit number formed by using the digits 4,3,0,8 is 3048.
v)Hundred million make one croe.
Answer Key
- (i) 131 (ii) 1 (iii) 1000 (iv) 760000 (v) 840000
- (i) False (ii) True (iii) True (iv) True (v) False
Whole Numbers
Q 1) Fill in the blanks
i)(4 X 5) X 3 = 4 X (5 X 3). This is all example of the ………….. of whole numbers.
ii)Sum of two whole numbers is a whole number. The name of this property is …………
iii)The identity element with respect to multiplication is ……………
iv)………….. is the smallest whole number.
v)There is no predecessor of …………… in whole numbers.
Q 2) True or False.
i)Division of any whole number by zero gives zero.
ii)1 is Multiplicative identity for whole numbers.
iii)Multiplication of any whole numbers by zero gives zero.
iv)Multiplication distributive over addition in whole numbers.
v)Every whole number has a successor.
Answer Key
1)(i) Associative property of multiplication
(ii) Closure property
(iii) 1
(iv) 0
(v) 0
2)(i) False
(ii) True
(iii) True
(iv) True
(v) True
Playing with Numbers
Q 1) Fill in the blanks.
i)HCF of two co-prime numbers ……………….
ii)LCM of 10, 15 and 20 is ……………….
iii)If a number has …………… is ones place, then it is divisible by 10.
iv)Any two ………………. Numbers are co – prime.
v)LCM of two or more numbers is divisible by their………………
Q 2) True or False.
i)1 is the first composite numbers.
ii)1 is factor of every number.
iii)HCF of two prime numbers is equal to their product.
iv)LCM of two co-prime numbers is equal to their product.
v)Maximum value of factor of a number is equal to number itself
Answer Key.
1)(i) 1 (ii) 60 (iii) 0 (iv) Consecutive (v) HCF
2)(i) False (ii) True (iii) False (iv) True (v) True
Basic Geometrical Ideas
Q 1) Fill in the blanks.
i)A dot gives an idea of a ……………….
ii)Rod for hanging curtain is an analogy of……………….
iii)Light through pin hole is an analogy of a …………….
iv)Picture of a river taken from statellite is an analogy of a…………...
v)A line segment has ……………… length.
Q 2) True or False
i)A point has a length and width
ii)Ray has infinite length
iii)There is one and only one line passing through two points.
iv)A line has no end point…………
v)Two intersecting lines can intersect each other at more than one point.
Answer Key.
1)(i) point (ii) Line segment (iii) Ray (iv) curve (v) definite / finite
2)(i) False (ii) True (iii) True (iv) True (v) False
Understanding Elementary Shapes
Q 1) Fill in the blanks.
i)A angle of measure greater than 180◦ is called ………………. Angle.
ii)………………. And …………… have the same number of faces, edges and vertices.
iii)An angle of 90 is known as ……………. angle.
iv)A triangle having all angles …………… than 90 is called an acute angled triangle.
v)An ……………… angle measures between 90 and 180
Q 2) True or False.
i)It is not possible to draw a triangle having two of its angles to 90.
ii)A perpendicular always bisects a line segment into two equal parts.
iii)An angle whose measure is less than of a right angle is called an obtuse angle.
iv)A quadrilateral is a polygon which has four sides.
v)The diagonals of rhombus are equal in length.
Answer Key.
1)(i) reflex (ii) cube, cuboid (iii) right (iv) less (v) obtuse
2)(i) True (ii) False(iii) False (iv) True (v) False
Integers
Q 1) Fill in the blanks.
i)The additive inverse of -1 is ……………
ii)(-11) + (-2) + (-1) = ……………….
iii)…………… + (-11) + 111 = 130.
iv)(-80) + 0 + (-90) = ……………...
v)……………… -3456 = -8910.
Q 2) True or False
i)0 is either positive or negative.
ii)-1 is greatest of all the negative integers.
iii)The sum of two negative integers is always less than zero.
iv)The sum of an integer and its negative is zero.
v)The sum of two positive integers is always less than zero
Answer Key.
1)(i) 1 (ii) -14 (iii) 30 (iv) -170 (v) -5454
2)(i) False (ii) True (iii) True (iv) True (v) False
Fractions
Q 1) Fill in the blanks.
i)6/11 and 6/13 are ………………. Proper fractions.
ii)The fraction 6/15 in simplest form is ……………….
iii)The fraction 17/34 in simplest form is ……………..
iv)18/135 and 90/675 are proper, unlike and …………. fractions.
v)8 2/7 is equal to the improper fraction ………………
Q 2) True or False.
i)48 minutes out of 2 hours represents 3/5.
ii)x/7 and 22/154 are equivalent fractions for x = 1.
iii)1 3/7 is a proper fraction.
iv)All improper fractions can be written as mixed fractions.
v)1/7, 2/7, 3/7 are all unit fractions
Answer Key.
1)(i) Unlike (ii) 2/5 (iii) 1/2 (iv) equivalent (v) 58/7
2)(i) False (ii) True (iii) False (iv) True (v) False