AutoSieve

Explore Patterns and Primes

Click on a number to mark it and shade all of its multiples, or click here to mark all of the prime numbers.

On this 5-by-20 grid, once you once you click on a number larger than 10, all of the remaining white squares will be prime numbers.

Width: Height: Color scheme:  More... Update

1 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
Creative Commons License
Autosieve by Rolfe R. Schmidt is licensed under a Creative Commons Attribution 3.0 United States License.