LCM Formula Explained, With Examples
Every lcm result comes from one formula. Once you understand what goes into it, you can sanity-check any figure you are given, whether by an employer, a bank, a teacher or another website.
The formula
lcm(a, b) = |a × b| ÷ gcd(a, b).
What each input means
- Numbers (separated by commas): the value you enter in the calculator.
Example
For example, with these inputs:
- Numbers (separated by commas): 4, 6, 10
the calculator returns:
- Least common multiple: 60
Why it matters
These calculations come up in school, at work and in daily life, from PSLE and O-Level practice to measuring a room for new flooring. Doing them by hand builds understanding, and a calculator lets you check the answer instantly.
Calculators are best used to check working rather than replace it, especially for exams where method marks count. Work the problem by hand first, then confirm with the calculator.
Each formula has assumptions built in. Area formulas assume flat shapes, volume formulas assume regular solids and statistical measures assume the data you enter is the data you want to describe. Knowing the assumptions helps you pick the right tool.
These calculations appear throughout the Singapore syllabus, from primary school percentages and fractions to secondary school algebra and geometry. Understanding the formula makes problem sums easier because you can recognise which quantity is missing.
Related calculations
- Volume of a Cube Calculator: Calculates the volume of a cube from the measurements you enter.
- Volume of a Cuboid Calculator: Calculates the volume of a cuboid from the measurements you enter.
- Volume of a Sphere Calculator: Calculates the volume of a sphere from the measurements you enter.
- Volume of a Cylinder Calculator: Calculates the volume of a cylinder from the measurements you enter.
Use the LCM Calculator to plug in your own numbers.
Run your own numbers: LCM Calculator