TERM 1 2013-14 / Name:
Grade: 5
Section:
Q.1 Fill in the blanks:
A. ____1______is the number having exactly one factor.
B. The smallest composite odd number is __9______.
C. HCF of two consecutive even numbers is __2______.
D. The smallest prime number greater than 20 is ____23______.
E. HCF of 52 and 65 is ____13______.
F. The least number that is exactly divisible by 18, 24 and 36 is ___72______.
G. HCF of two numbers is a factor of their _____LCM______.
H. If a number is divided by its factor, the remainder is always _____Zero______.
I. The greatest 2-digit prime number is ____97______.
J. The total number of prime number upto 100 is ___25______.
Q.2 Which of the following statements are true?
A) The LCM of given numbers is always greater than any number. ___T______
B) If a number is divisible by 3 it must be divisible by 9. ___F______
C) The sum of consecutive odd numbers is always divisible by 4. ____T______
D) If a number divides the sum of two numbers it must exactly divide the numbers separately. ____F_____
E) The HCF of two co primes is always 1. ____T______
F) 1 is the smallest prime number. _____F______
G) Odd numbers are not multiples of 2. ____T______
H) The sum of two prime numbers is always a prime number. ______F____
I) A composite number can be written as the sum of two primes. _____T_____
J) Every number has at least two factors. ____T______
Q.3 Find the factors of the following by prime factorization method:
A) 43353 X 5 X 17 X 17 / B) 1080
2 X 2 X 2 X 3 X 3 X 3 X 5
C) 216
2 X 2 X 2 X 3 X 3 X 3 / D) 980
2 X 2 X 5 X 7 X 7
Q.4 Find the H.C.F and L.C.M of the following numbers:
A) 84, 120 and 138HCF: 6
LCM: 2 X 2 X 2 X 3 X 5 X 7 X 23 = 19320 / B) 81, 117
HCF: 9
LCM: 3 X 3 X 3 X 3 X 13 = 1053
C) 630 and 1188
HCF: 18
LCM: 2 X 2 X 3 X 3 X 3 X 5 X 7 X 11 = 41580 / D) 34, 40 and 126
HCF: 2
LCM: 42820
Q.5: In a morning walk, three persons step off together. Their steps measure 80 cm, 70 cm and 75 cm respectively. What is the minimum distance each should walk so that all can cover the same distance in complete steps?
LCM: 2 X 5 X 8 X 7 X 15 = 8400cm. The required minimum distance is 84 m
Q.6 The length, breadth and height of a room are 825 cm, 675 cm and 450 cm respectively. Find the longest tape that can measure the three dimensions of the room exactly.
HCF = 75. The required length of the tape = 75 cm.
1 | Page Source: Mathematics in Everyday Life