Prime Number Checker
Checks whether a number is prime.
Result
- Result
- 97 is a prime number
How to use the prime number checker
- Enter the whole number.
- The results update as you type, or press Calculate.
- Read the result first, then the supporting figures below it.
Formula
Test divisors up to √n.
Worked example
For example, with these inputs:
- Whole number: 97
the calculator returns:
- Result: 97 is a prime number
Background
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.
Rounding is a common source of small errors. Keep full precision during intermediate steps and round only the final answer to the number of decimal places or significant figures the question asks for.
Frequently asked questions
How does the prime number checker work?
It applies this formula: Test divisors up to √n.
Can I use any units?
Yes, as long as every input uses the same unit. The answer will be in that unit (squared for areas, cubed for volumes).