Page 45 - Revised Maths Wisdom Class - 6

Prime Time 43

ILLUSTRATIONS

Example 1: Find the prime factors of 352 by Example 2: Find the prime factors of 2904 by
factor tree method. factor tree method.
Solution: 352 Solution: 2904

2 176 2 1452

2 88 2 726

2 44 2 363

2 22
3 121

2 11
11 11
Thus, 352 = 2 × 2 × 2 × 2 × 2 × 11

Thus, 2904 = 2 × 2 × 2 × 3 × 11 × 11

Example 3: Using division method, find the prime Example 4: Using division method, find the
factors of 1512. prime factors of 164.
Solution: 2 1512 Solution: 2 164
2 756 2 82

2 378 41 41
3 189 1
3 63 Thus, 164 = 2 × 2 × 41

3 21
7 7
1

Thus, 1512 = 2 × 2 × 2 × 3 × 3 × 3 × 7

Example 5: Write the greatest 6-digit number and express it as a product of primes.
Solution: The greatest 6-digit number = 999999
3 999999

3 333333
3 111111

7 37037
11 5291
13 481
37 37

1 Thus, 999999 = 3 × 3 × 3 × 7 × 11 × 13 × 37