How well do you know your prime numbers? Challenge your friends to this Sporcle quiz!
Have a go at this worksheet to find all the Prime Numbers less than 100.
Now try this much bigger Sieve to find all the Prime Numbers less than 400! Start by clicking on 2 and all the multiples of 2 will be removed. Then click on 3 to remove the multiples of 3 and continue clicking on the prime numbers until you are only left with red prime numbers.
Also take a look at this video
Here’s another great starter from Transum
The multiples of 4 are all the numbers in the 4 times table. 4,8,12,16,20,24,28,32……..
A prime number is special because it only has 2 factors. These two factors are always 1 and the number itself. So 7 is a prime number because the factors of 7 are 1 and 7.