SIEVE OF ERATOSTHENES TO 150 - How to find primes up to 150

Oct 22, 2026

Uploaded by hdkawk

A step-by-step sieve method identifies prime numbers up to 150. The process starts at 2, circles it, and cross out all multiples of each selected prime. It then moves to the next number not crossed out (e.g., 3, then 5) and repeats the same circle-and-cross-out routine. A grid from 2 to 150 is provided, with highlighted cells representing primes, concluding with the count of primes between 1 and 150 as 35.

LanguageEnglish

CategoryExam

FormatPDF

Pages2

Reading Time5 min

AccessFree to download

How the Sieve Works

Steps to circle primes

Result and prime count

Name Date SIEVE OF ERATOSTHENES TO 150 • Start at number 2. Put a circle it. Cross out all the multiples of that number. • Move on to the next number you have not crossed out (3) . Put a circle round it. Cross out all the multiples of that number. • Move on to the next number not crossed out (5) . Repeat. | | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 | | 101 | 102 | 103 | 104 | 105 | 106 | 107 | 108 | 109 | 110 | | 111 | 112 | 113 | 114 | 115 | 116 | 117 | 118 | 119 | 120 | | 121 | 122 | 123 | 124 | 125 | 126 | 127 | 128 | 129 | 130 | | 131 | 132 | 133 | 134 | 135 | 136 | 137 | 138 | 139 | 140 | | 141 | 142 | 143 | 144 | 145 | 146 | 147 | 148 | 149 | 150 | How many prime numbers are there between 1 and 150? Name Date SIEVE OF ERATOSTHENES TO 150 ANSWERS • The numbers highlighted are all primes. | | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 | | 101 | 102 | 103 | 104 | 105 | 106 | 107 | 108 | 109 | 110 | | 111 | 112 | 113 | 114 | 115 | 116 | 117 | 118 | 119 | 120 | | 121 | 122 | 123 | 124 | 125 | 126 | 127 | 128 | 129 | 130 | | 131 | 132 | 133 | 134 | 135 | 136 | 137 | 138 | 139 | 140 | | 141 | 142 | 143 | 144 | 145 | 146 | 147 | 148 | 149 | 150 | How many prime numbers are there between 1 and 150? 35

FAQs

What is the first number to start with in the sieve up to 150?

Start at number 2, circle it, and cross out all its multiples.

How do you choose the next prime in the sieve process?

Move on to the next number you have not crossed out and circle it, then cross out all of its multiples.

How many prime numbers are there between 1 and 150?

There are 35 prime numbers between 1 and 150.

Oct 22, 2026

Uploaded by hdkawk