Compare the Two Common Fractions 75/100 and 84/108, Which One is Larger? Online Calculator

Fractions 75/100 and 84/108 are compared by building equivalent fractions, which have either equal denominators or equal numerators

To compare and sort multiple fractions, they should either have the same denominator or the same numerator.

The operation of comparing fractions:
75/100 and 84/108

Simplify the operation
Reduce (simplify) the fractions to their lowest terms equivalents:


The fraction: 75/100

  • The prime factorizations of the numerator and denominator:
  • 75 = 3 × 52
  • 100 = 22 × 52
  • Multiply all the common prime factors: if there are repeating prime factors we only take them once, and only the ones having the lowest exponent (the lowest powers).
  • GCF (75; 100) = 52 = 25

75/100 = (75 ÷ 25)/(100 ÷ 25) = 3/4


The fraction can also be reduced without calculating GCF; factor the numerator and denominator and cross out all the common prime factors:


75/100 = (3 × 52)/(22 × 52) = ((3 × 52) ÷ 52)/((22 × 52) ÷ 52) = 3/4



The fraction: 84/108

  • 84 = 22 × 3 × 7
  • 108 = 22 × 33
  • GCF (84; 108) = 22 × 3 = 12

84/108 = (84 ÷ 12)/(108 ÷ 12) = 7/9


The fraction can also be reduced without calculating GCF; factor the numerator and denominator and cross out all the common prime factors:


84/108 = (22 × 3 × 7)/(22 × 33) = ((22 × 3 × 7) ÷ (22 × 3))/((22 × 33) ÷ (22 × 3)) = 7/9




To compare and sort the fractions, make their numerators the same.

To make the fractions' numerators the same - we have to:

  • 1) calculate their common numerator
  • 2) calculate the expanding number of each fraction
  • 3) expand the fractions to equivalent forms having equal numerators

Calculate the common numerator

The common numerator is nothing else than the least common multiple (LCM) of the numerators of the fractions.


To calculate the LCM, we need the prime factorization of the numerators:


3 is a prime number.

7 is a prime number.


Multiply all the unique prime factors: if there are repeating prime factors we only take them once, and only the ones having the highest exponent (the highest powers).




Calculate the expanding number of each fraction:

Divide the LCM by the numerator of each fraction.


3/4 ⟶ 21 ÷ 3 = (3 × 7) ÷ 3 = 7


7/9 ⟶ 21 ÷ 7 = (3 × 7) ÷ 7 = 3




Make the numerators of the fractions the same:

  • Expand each fraction: multiply both its numerator and denominator by its corresponding expanding number, calculated above.
  • This way all the fractions will have the same numerator:

3/4 = (7 × 3)/(7 × 4) = 21/28


7/9 = (3 × 7)/(3 × 9) = 21/27




The fractions have the same numerator, compare their denominators.

The larger the denominator the smaller the positive fraction.


The larger the denominator the larger the negative fraction.


::: The operation of comparing fractions :::
The final answer:

The fractions sorted in ascending order:
21/28 < 21/27

The initial fractions sorted in ascending order:
75/100 < 84/108

How are the numbers written: comma ',' used as a thousands separator; point '.' as a decimal separator; numbers rounded off to max. 12 decimals (if the case). Used symbols: '/' the fraction bar; ÷ dividing; × multiplying; + plus (adding); - minus (subtracting); = equal; ≈ approximately equal.

Compare and sort common fractions, online calculator:

Tutoring: Comparing ordinary fractions

How to compare two fractions?

1. Fractions that have different signs:

  • Any positive fraction is larger than any negative fraction:
  • ie: 4/25 > - 19/2

2. A proper and an improper fraction:

  • Any positive improper fraction is larger than any positive proper fraction:
  • ie: 44/25 > 1 > 19/200
  • Any negative improper fraction is smaller than any negative proper fraction:
  • ie: - 44/25 < -1 < - 19/200

3. Fractions that have both like numerators and denominators:

  • The fractions are equal:
  • ie: 89/50 = 89/50

4. Fractions that have unlike (different) numerators but like (equal) denominators.

  • Positive fractions: compare the numerators, the larger fraction is the one with the larger numerator:
  • ie: 24/25 > 19/25
  • Negative fractions: compare the numerators, the larger fraction is the one with the smaller numerator:
  • ie: - 19/25 < - 17/25

5. Fractions that have unlike (different) denominators but like (equal) numerators.

  • Positive fractions: compare the denominators, the larger fraction is the one with the smaller denominator:
  • ie: 24/25 > 24/26
  • Negative fractions: compare the denominators, the larger fraction is the one with the larger denominator:
  • ie: - 17/25 < - 17/29

6. Fractions that have different denominators and numerators (unlike denominators and numerators).

More on ordinary (common) fractions / theory: