SBP-Program

f

tw

in

Adding mixed fractions with unlike denominators

How to add mixed fractions with unlike denominators?

Examples of adding mixed fractions with unlike denominators

Problem: Add mixed fractions with unlike denominators

15 + 25
1812

Solution.

1. Add the whole numbers of the mixed fractions

1 + 2 = 3

2. Add the fractions

5 + 5
1812

The denominators are 18 and 12.

The least common multiple of 18 and 12:

lcm(18, 12) = 36

See least common multiple 12 and 18.

The least common multiple is the lowest common denominator of the fractions.

So, the lowest common denominator of the fractions is 36.

Change the first fraction to the lowest common denominator

5 * 2 = 10
18 * 236

Change the second fraction to the lowest common denominator

5 * 3 = 15
12 * 336

Add the fractions

10 + 15 = 25
363636

3. Combine the whole and fraction parts

3 + 25 = 325
3636

Answer

55 + 25 = 325
181236