If possible without calculating: Tell whether the fraction is a lowest terms fraction.
Simplify (or reduce) a fraction by dividing both the numerator and the denominator by the simplification number.
A lowest terms fraction can not be simplified further.
If you would like to have a vivid explanation with a detailed example, please read the page Simplifying/Reducing Fractions - Learn this magic trick!
Step 1: Test, if the numerator or the denominator is equal to 1.
If the numerator or the denominator is equal to 1, the fraction is simplified to lowest terms.
Since this is not the case, go on to the next test:
Step 2: Test, if the numerator or the denominator is a prime number
If the numerator or the denominator is a prime number and they are not multiples, the fraction is simplified to lowest terms!
In this case, whether the numerator nor the denominator is a prime number. Go on to the next test:
Step 3: Test, if the numerator and the denominator both are divisible by 10, 5 or 2
You can see from the last digit, if a number is divisible by 10, 5 or 2.
The fraction can not be simplified by 10, 5 or 2. Go on to the next test:
Step 4: Test, if the numerator and the denominator both are divisible by 3 or 9
Calculate the cross sum of the numerator and the cross sum of the denominator:
Numerator: 1 + 8 = 9
Denominator: 1 + 5 = 6
The cross sums are both divisible by 3.
The fraction can be simplified further, namely the number 3.
