Factor Trees
Create factor trees to find the prime factors of the given numbers.
HCF and LCM
Practise finding the highest common factor (H.C.F), sometimes called the greatest common divisor, and the lowest common multiple (L.C.M) of two numbers.
This is the main Transum help video on LCM.
HCF and LCM Video
Learn different methods for finding the highest common factor and lowest common multiple of two or three numbers.
Christmas Bells
If all the bells ring together at noon, at what time will they next all ring together? This problem requires the use of LCM.
Dancing
Work out how many people were at the dance from the clues given.
Hotel Digital
A puzzle about the lifts in a hotel which serve floors based on the day of the week.
Name Again
Work out what the nth letter will be in a recurring pattern of letters in a person's name
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Teachers might find the complete LCM Topic List useful.
LCM stands for lowest common multiple or least common multiple. The LCM of two (or more numbers) is the smallest number that both of the numbers divide into exactly. Being able to find the LCM is useful when trying to find a common denominator when adding two fractions together. The LCM also describes the points when two (or more) periodic repetitions coincide.
HCF stands for highest common factor which is also known as the greatest common factor. The HCF of two (or more) numbers is the largest number that divides into the two numbers exactly. Being able to find the HCF is useful in everyday organisational tasks and also when factorising algebraic expressions.
