Multiples https://www.bbc.co.uk/bitesize/topics/zqbg87h/articles/zgbpnbk Factors https://www.bbc.co.uk/bitesize/topics/zfq7hyc/articles/zp6wfcw Prime https://www.bbc.co.uk/bitesize/topics/zfq7hyc/articles/z2q26fr Punctuating speech https://www.bbc.co.uk/bitesize/topics/zvwwxnb/articles/z8d78hv