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106 LearnersLast updated on September 11, 2025

Calculators are reliable tools for solving simple mathematical problems and advanced calculations like number theory. Whether you’re exploring prime numbers, cryptography, or modular arithmetic, calculators will make your life easy. In this topic, we are going to talk about Fermat's Little Theorem calculators.
A Fermat's Little Theorem calculator is a tool to determine results in modular arithmetic using Fermat's Little Theorem.
This theorem states that if p is a prime number and a is an integer not divisible by p , then ap-1 ≡ 1p mod(p) .
This calculator helps perform these calculations much easier and faster, saving time and effort.
Given below is a step-by-step process on how to use the calculator:
Step 1: Enter the base a and the prime p : Input the integers into the given fields.
Step 2: Click on calculate: Click on the calculate button to compute ap-1 ≡ 1p mod(p) and get the result.
Step 3: View the result: The calculator will display the result instantly.
Fermat's Little Theorem is used to simplify calculations in modular arithmetic.
It states that for a prime p and an integer a such that p does not divide a : ap-1 ≡ 1p mod(p)
This theorem is particularly useful in computing large powers modulo a number, especially in cryptography.
When we use a Fermat's Little Theorem calculator, there are a few tips and tricks that we can use to make it a bit easier and avoid mistakes:
Ensure that p is a prime number; otherwise, the theorem does not apply.
Remember that a should not be divisible by p for the theorem to work.
Use the theorem to simplify calculations of large powers in modular arithmetic.
We may think that when using a calculator, mistakes will not happen. But it is possible for children to make mistakes when using a calculator.
Calculate \( 7^{16} \mod 17 \).
Use Fermat's Little Theorem:
Since 17 is prime, 716 ≡1 pmod (17).
Thus, 716 mod 17 = 1 .
According to Fermat's Little Theorem, for ap-1 ≡ 1p mod(p) p prime and a not divisible by p .
Determine \( 3^{22} \mod 23 \).
Use Fermat's Little Theorem:
Since 23 is prime, 322 ≡1 pmod23.
Thus, 322 mod 23 = 1.
Fermat's Little Theorem simplifies the calculation to 1 since 23 is prime and 3 is not divisible by 23.
Find \( 5^{10} \mod 11 \).
Use Fermat's Little Theorem:
Since 11 is prime, 510 ≡ 1 pmod(11).
Thus, 510 mod 11 = 1.
The theorem applies as 11 is prime and 5 is not divisible by 11.
Compute \( 2^{100} \mod 101 \).
Use Fermat's Little Theorem:
Since 101 is prime, 2100 ≡1 pmod(101).
Thus, 2100 mod 101 = 1.
According to Fermat's Little Theorem, a prime p and a not divisible by p satisfy the theorem.
Evaluate \( 9^{14} \mod 13 \).
Use Fermat's Little Theorem:
Since 13 is prime, 912 ≡1 pmod(13).
Thus, 914 = 912 × 92 ≡ 1 × 81 ≡ 3 pmod(13).
Using the theorem and simplifying powers, we find the result is 3 modulo 13.
Seyed Ali Fathima S a math expert with nearly 5 years of experience as a math teacher. From an engineer to a math teacher, shows her passion for math and teaching. She is a calculator queen, who loves tables and she turns tables to puzzles and songs.
: She has songs for each table which helps her to remember the tables






