5. Find the prime factors of the following numbers.
a) 15
b) 20
c) 27
d) 30
e) 36
f) 42
g) 48
h) 63

6. Find the first five multiples of the following numbers.
a) 2
b) 3
c) 5
d) 6
e) 8
f) 10
g) 11
h) 12
i) 15
j) 20
k) 25
l) 30

7. Round off the following numbers to the nearest ten.
a) 642
b) 8745
c) 49386
d) 84
e) 9087
f) 55555

8. Round off the following numbers to the nearest hundred.
a) 347
b) 4892
c) 7830
d) 4894
e) 66347
f) 56675

9. Round off the following numbers to the nearest thousand.
a) 6242
b) 66732
c) 48934
d) 58327
e) 67562
f) 34082

Project work



Answer :

Sure, let's go through the solution step by step for each part of your questions.

### 5. Find the prime factors of the following numbers.
Prime factors are the prime numbers that divide a number exactly, without leaving a remainder.

a) 15
- Prime factors: 3, 5
- Explanation: 15 can be divided by 3 (15 ÷ 3 = 5) and 5 (5 ÷ 5 = 1).

b) 20
- Prime factors: 2, 2, 5
- Explanation: 20 can be divided by 2 repeatedly until it cannot be divided further (20 ÷ 2 = 10, 10 ÷ 2 = 5) and then by 5 (5 ÷ 5 = 1).

c) 27
- Prime factors: 3, 3, 3
- Explanation: 27 can be repeatedly divided by 3 (27 ÷ 3 = 9, 9 ÷ 3 = 3, 3 ÷ 3 = 1).

d) 30
- Prime factors: 2, 3, 5
- Explanation: 30 can be divided by 2 (30 ÷ 2 = 15), then by 3 (15 ÷ 3 = 5), and lastly by 5 (5 ÷ 5 = 1).

e) 36
- Prime factors: 2, 2, 3, 3
- Explanation: 36 can be divided by 2 repeatedly (36 ÷ 2 = 18, 18 ÷ 2 = 9) and then by 3 repeatedly (9 ÷ 3 = 3, 3 ÷ 3 = 1).

f) 42
- Prime factors: 2, 3, 7
- Explanation: 42 can be divided by 2 (42 ÷ 2 = 21), then by 3 (21 ÷ 3 = 7), and lastly by 7 (7 ÷ 7 = 1).

g) 48
- Prime factors: 2, 2, 2, 2, 3
- Explanation: 48 can be divided by 2 repeatedly (48 ÷ 2 = 24, 24 ÷ 2 = 12, 12 ÷ 2 = 6, 6 ÷ 2 = 3) and then by 3 (3 ÷ 3 = 1).

h) 63
- Prime factors: 3, 3, 7
- Explanation: 63 can be divided by 3 repeatedly (63 ÷ 3 = 21, 21 ÷ 3 = 7) and then by 7 (7 ÷ 7 = 1).

### 6. Find the first five multiples of the following numbers.
Multiples are the results of multiplying a number by integers.

a) 2
- Multiples: 2, 4, 6, 8, 10

b) 3
- Multiples: 3, 6, 9, 12, 15

c) 5
- Multiples: 5, 10, 15, 20, 25

d) 6
- Multiples: 6, 12, 18, 24, 30

e) 8
- Multiples: 8, 16, 24, 32, 40

f) 10
- Multiples: 10, 20, 30, 40, 50

g) 11
- Multiples: 11, 22, 33, 44, 55

h) 12
- Multiples: 12, 24, 36, 48, 60

i) 15
- Multiples: 15, 30, 45, 60, 75

j) 20
- Multiples: 20, 40, 60, 80, 100

k) 25
- Multiples: 25, 50, 75, 100, 125

l) 30
- Multiples: 30, 60, 90, 120, 150

### 7. Round off the following numbers to the nearest ten.
When rounding to the nearest ten, if the units digit is 5 or more, round up; if it's 4 or less, round down.

a) 642
- Rounded to: 640

b) 8745
- Rounded to: 8740

c) 49386
- Rounded to: 49390

d) 84
- Rounded to: 80

e) 9087
- Rounded to: 9090

f) 55555
- Rounded to: 55560

### 8. Round off the following numbers to the nearest hundred.
When rounding to the nearest hundred, if the tens digit is 5 or more, round up; if it's 4 or less, round down.

a) 347
- Rounded to: 300

b) 4892
- Rounded to: 4900

c) 7830
- Rounded to: 7800

d) 4894
- Rounded to: 4900

e) 66347
- Rounded to: 66300

f) 56675
- Rounded to: 56700

### 9. Round off the following numbers to the nearest thousand.
When rounding to the nearest thousand, if the hundreds digit is 5 or more, round up; if it's 4 or less, round down.

a) 6242
- Rounded to: 6000

b) 66732
- Rounded to: 67000

c) 48934
- Rounded to: 49000

d) 58327
- Rounded to: 58000

e) 67562
- Rounded to: 68000

f) 34082
- Rounded to: 34000

These results were derived using standard mathematical methods for finding prime factors, determining multiples, and rounding off numbers.