GCSE›Edexcel GCSE Maths›Mind mapsPrime Factors, HCF & LCMEdexcel GCSE Maths: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsPrimesExactly two factors: 1 and itself1 is not prime2 is the only even primeFactors divide in; multiples are the times tableFactorisingSplit with a factor tree until all primesWrite the answer in index form60=22×3×560 = 2^2 \times 3 \times 560=22×3×5Every integer above 1 has a unique factorisationFinding HCFMultiply lowest power of each common prime60=22×3×560 = 2^2\times3\times560=22×3×5, 84=22×3×784 = 2^2\times3\times784=22×3×7HCF =22×3=12= 2^2 \times 3 = 12=22×3=12HCF and LCMprime factors2357Finding LCMMultiply highest power of every prime usedLCM of 60 and 84 =420= 420=420Venn methodShared primes go in the overlapOverlap multiplied gives the HCFWhole diagram multiplied gives the LCM12 and 18: HCF 6, LCM 36Exam tipsGive prime factorisations in index formDo not call 1 a prime