∿Mixed Number Lab

Mixed number addition tool

Adding Mixed Numbers Calculator

Add two mixed numbers instantly and see every step - from finding the LCD to simplifying the result. Free, mobile-friendly, and shareable.

FreeStep-by-stepGrade 4-6Instant answer

Updated

2026-03-20

Want the full method?

Open the complete guide

Calculator

Add mixed numbers - enter values and press Calculate

Operand A

Enter a whole part and a fraction.

Use +/- or drag a field sideways to adjust quickly.

Operand B

Enter a whole part and a fraction.

Use +/- or drag a field sideways to adjust quickly.

Choose an operator

Open history

History

Your last 10 calculations

Your solved problems appear here for one-tap reload.

How it works

How the calculator works

The calculator shows the same core arithmetic students are expected to write, but in a shorter format focused on getting the answer and checking each step.

Add mixed numbers in three steps

  1. 1

    Convert to improper fractions

    1frac12 = frac32,quad 2frac14 = frac94
  2. 2

    Find the LCD and add

    frac64 + frac94 = frac154
  3. 3

    Simplify and convert back

    frac154 = 3frac34
See the full adding mixed numbers guide with 3 methods and 10+ examples

Examples

Worked examples

Example 1

1 1/2 + 2 1/4

Simple: unlike denominators, no regrouping

Answer: 3 3/4

  1. 1.Convert 1 1/2 to 3/2 and 2 1/4 to 9/4.
  2. 2.Rename 3/2 as 6/4, then add 6/4 + 9/4 = 15/4.
  3. 3.Convert 15/4 back to 3 3/4.

Try this in the calculator ↑

Example 2

2 3/4 + 1 2/3

Medium: unlike denominators with regrouping

Answer: 4 5/12

  1. 1.Convert to 11/4 + 5/3.
  2. 2.Use LCD 12: 33/12 + 20/12 = 53/12.
  3. 3.Convert 53/12 to 4 5/12.

Try this in the calculator ↑

Example 3

3 5/6 + 2 7/8

Harder: larger LCD

Answer: 6 17/24

  1. 1.Convert to 23/6 + 23/8.
  2. 2.Use LCD 24: 92/24 + 69/24 = 161/24.
  3. 3.Convert 161/24 to 6 17/24.

Try this in the calculator ↑

Tips

Common mistakes to avoid

Wrong: Adding denominators, such as 1/2 + 1/3 = 2/5.

Right: Find the LCD first, then add only the numerators.

Wrong: Forgetting to regroup when the fraction part is 1 or more.

Right: If the fraction sum is 5/4, convert it to 1 1/4 and add the extra whole.

Related

Related tools and guides

How to Add Mixed Numbers (full guide)

Learn the complete addition method with more examples and visual support.

Subtracting Mixed Numbers Calculator

Use the matching calculator for subtraction and borrowing practice.

Fraction Calculator

A broader fraction calculator for pure fraction operations.

Mixed Number Calculator

Return to the full mixed number calculator hub.

Simplify Fractions

Reduce final answers to lowest terms after calculating.

Mixed Number to Improper Fraction

Review the conversion step used before most mixed number operations.