For the division of quantities
LCM is used to find the lowest common denominator in fractions HCF is used to reduce fractions to their simplest terms
The HCF helps when reducing fractions. The LCM helps when adding or subtracting fractions.
In finding the LCM or HCF of two or more numbers
You would use it when adding fractions.
weighing scales
You use the LCM when you want to add or subtract fraction and then you can use the HCF to simplify the result. You may want to do this when budgeting: for example one quarter of your pay goes on rent, two fifths goes on food and drink, and so on. So how much of your pay is available for discretionary spending?
Use GCF instead of HCF. 6 and 30 would be those numbers...
2 and 20 have an HCF of 2 and an LCM of 20. You could also use 4 and 10.
you are doing it right now. Unless you are dead, then that means I'm discussing this with a zombie.
Chefs, carpenters, anyone who has to add, subtract or simplify fractions.
Any job where you need to add or subtract fractions.