Factorial: 5 Mistakes to Avoid
Calculates n factorial up to 170. The maths is not complicated, but a handful of errors come up again and again in this and related math & geometry calculations. Here is what to watch for.
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.
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.
1. Dropping negative signs
Signs matter for roots, changes and differences.
2. Rounding too early
Rounding intermediate steps can throw the final answer off.
3. Forgetting the order of operations
Powers and brackets come before multiplication and addition.
4. Confusing radius and diameter
Many circle formulas use the radius, which is half the diameter.
5. Population versus sample formulas
Sample standard deviation divides by n − 1; population divides by n.
The correct method
n! = 1 × 2 × … × n.
For example, with these inputs:
- n: 10
the calculator returns:
- n!: 3,628,800
Related calculations
- Fraction Simplifier: Reduces a fraction to its lowest terms.
- Ratio Simplifier: Simplifies a ratio.
- Decimal to Fraction Converter: Converts a decimal to a fraction.
- Scientific Notation Converter: Writes a number in scientific notation.
The Factorial Calculator applies the formula consistently, so it is a quick way to double-check your own working.
Run your own numbers: Factorial Calculator