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numbergrid [prime numbers]

numbergrid [prime numbers]
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
typewriterscript []
[News Flash]
PRIME numbers are natural numbers that are divisible by only 1 and the number itself. An example of a PRIME number is 13. That is because it can only be divided by 1 and 13 without a remainder. Simply click on all of the numbers in the grid which are NOT PRIME NUMBERS. They will disappear and you will be left with a set of numbers which are PRIME NUMBERS. Count them and put the answer into the quiz below the activity. To restart the activity just refresh the page.


1 question quiz
How many numbers remain? 21 22 23 24 25 26 27 28