Sum Calculator - Add Multiple Numbers

Calculate the sum of multiple numbers instantly. Add comma-separated values, see running totals, partial sums, and average.

Sum Calculator

Add multiple numbers instantly - see the total, count, and average

About Sum

What is Sum?

The sum is the result of adding two or more numbers together. It's one of the most basic arithmetic operations and is used in countless applications.

Sum Formula:

Sum = a + b + c + ... + n

Common Uses:

  • Totalling expenses or income
  • Adding test scores
  • Calculating totals in spreadsheets
  • Finding the sum of a series
  • Financial calculations

Sum Properties:

  • Commutative: a + b = b + a (order doesn't matter)
  • Associative: (a + b) + c = a + (b + c)
  • Identity: a + 0 = a (adding zero doesn't change)
  • Inverse: a + (-a) = 0

Example:

Find the sum of: 5, 8, 12, 15, 20

Sum = 5 + 8 + 12 + 15 + 20 = 60

About This Calculator

Sum Calculator - Add Multiple Numbers

Calculate the sum of multiple numbers instantly with our free online sum calculator. Add numbers separated by commas, spaces, or new lines and get the total, count, and average.

What is Sum?

The sum is the result of adding two or more numbers together. It's one of the four basic arithmetic operations and is fundamental to mathematics.

Sum Formula

Sum = a + b + c + ... + n

Example Calculation

Find the sum of: 5, 8, 12, 15, 20

Sum = 5 + 8 + 12 + 15 + 20
Sum = 60

How to Use This Calculator

  1. Enter Numbers - Input values separated by commas, spaces, or new lines
  2. Choose Precision - Select decimal places for results
  3. Calculate - View sum, count, and average
  4. Partial Sums - Toggle to see running totals

Properties of Addition

Commutative Property

The order of numbers doesn't change the sum.

a + b = b + a
Example: 3 + 5 = 5 + 3 = 8

Associative Property

Grouping doesn't change the sum.

(a + b) + c = a + (b + c)
Example: (2 + 3) + 4 = 2 + (3 + 4) = 9

Identity Property

Adding zero doesn't change the value.

a + 0 = a
Example: 7 + 0 = 7

Inverse Property

Adding a number's inverse gives zero.

a + (-a) = 0
Example: 5 + (-5) = 0

Sum Applications

Finance

  • Total expenses for a month
  • Sum of all invoices
  • Adding income sources
  • Calculating totals

Education

  • Total test points earned
  • Sum of assignment scores
  • Grade calculations
  • Average preparation

Business

  • Total sales revenue
  • Sum of daily transactions
  • Inventory totals
  • Performance metrics

Running Total (Partial Sums)

A running total shows the sum at each step of addition.

Example: 5, 8, 12, 15, 20

StepValueRunning Sum
155
2813
31225
41540
52060

Sum Notation

In mathematics, the Greek letter sigma (Σ) represents sum:

Sum from i=1 to n of xi = x1 + x2 + ... + xn

This notation is used in statistics, calculus, and many other fields.

Practice Problems

Problem 1

Find the sum of: 10, 20, 30, 40, 50

Solution: Sum = 150

Problem 2

A student scored 85, 92, 78, 88 on tests. What's the total?

Solution: Sum = 343

Frequently Asked Questions

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