Addition '+' | Basics of Arithmetic

See Also: What are Numbers?

This page is part of our series covering the basics of arithmetic, the simplest way of manipulating numbers.

Here you'll learn the basics of Addition (+) how to add, sum or 'bring together' two or more numbers to make a new number - a total. The ability to 'Add up' is important in all aspects of life, at home, school, work and socially.

See our other pages to learn about: Subtraction, Multiplication and Division.


Addition Quick Facts:


  • Addition is the term used to describe adding two or more numbers together. 
  • The plus sign ‘+‘ is used to denote an addition: 2 + 2. 
  • The + can be used multiple times as required: 2 + 2 + 2. 
  • For longer lists of numbers it is usually easier to write the numbers in a column and preform the calculation at the bottom. 
  • The word 'sum' or the symbol may also be used for addition.
  • It doesn’t matter in which order you add a group of numbers together as the answer will always be the same:
    1 + 2 + 3 + 4 gives the same answer (10) as 4 + 2 + 1 + 3
  • Adding 0 to any number makes no difference 2 + 0 = 2.

Basic addition is a step on from counting and usually picked up easily by learners.

Once a learner can count to ten they can usually quickly perform additions up to ten.

For example, if a learner is given two piles of cards, one pile containing 4 cards and the other containing 3 cards, they can count all the cards and come up with the answer: 7. 

Using fingers is common when learning how to count and add. Adding dots drawn on a piece of paper is the next step in learning addition, this time there are no physical items to handle. 

Finally when digits are recognised the same sum can be performed by looking at 3 + 4.

Adding the same number to itself (or doubling) is also fairly straightforward once a basic understanding of multiplication has been grasped,   3 + 3 = 6 for example. 

Adding the same number to itself is the same as multiplying a number by 2:

3 + 3 can also be written as
3 x 2 (verbally 3 times 2).


Formal Addition

When adding lots of numbers together it is helpful to write them in columns, denoting units, tens and hundreds (see our numbers page for examples of this). If we needed to add 4, 15, 23, 24, 35, 42

Step 1: Arrange the numbers in columns, Hundreds, Tens and Units as needed:

Tens Units
4
1 5
2 3
2 4
3 5
4 2

Add the numbers in the right (units) column. This should give you an answer of 23. Two tens and three units.  Write a 3 in the your total for the units column.

Carry over the 2 tens - it is usual to put this number underneath the total, we'll need it in the next step.

Tens Units
4
1 5
2 3
2 4
3 5
4 2
=
Total 3
Carried 2

Step 2: Add together the numbers in the tens column remembering to include the 2 that was carried over.  You should get an an answer of 14.

That is 4 tens (as we are working in the tens column) and 1 to carry over to the next column, hundreds.

Hundreds Tens Units
4
  1 5
  2 3
  2 4
  3 5
4 2
=
Total 4 3
Carried 1 2

Step 3: Add together the numbers in the tens column, remembering to include the 2 that was carried over. You should get an an answer of 14.

That is 4 tens (as we are working in the tens column) and 1 to carry over to the next column, hundreds.

Hundreds Tens Units
4
  1 5
  2 3
  2 4
  3 5
4 2
=
Total 1 4 3
Carried 1 2

There are no numbers in the hundreds column except for the 1 that was carried over from the tens column.

As there is nothing else to add bring the one up to the total.

We have no numbers left to add and therefore have arrived at our answer: 143.


Examples of Addition

There are many examples of when addition is useful in everyday situations. When working out a route for travel you may want to add up the number of miles (or kilometres) for each step of the journey to find the total number of miles you will travel. This could help you plan for fuel stops, for example.

You can use addition to work out how long something will take - for example if you get on the bus at 11:00 and the journey takes 25 minutes what time will you arrive? Similarly you can add up days, weeks, months or years.

Always remember when adding minutes or seconds that there are 60 seconds in a minute and 60 minutes in an hour. Therefore 100 minutes is not equal to an hour but 1 hour and 40 minutes.


Perhaps one of the most common everyday uses for addition is when working with money. For example, adding up bills and receipts. The following example is a typical receipt from a supermarket, add all the individual prices to find the total for the visit.

As SkillsYouNeed is a British site the currency symbol used is £ (Pounds) adding in $ (Dollars), € (Euros) or any other currency is the same - just change the currency symbol.

Cheddar Cheese    £2.99
Plain Flour £0.79
Granulated Sugar £1.20
Butter £1.24
Carrots £0.16
Household Cleaner £1.89
Milk £1.25
Milk Chocolate £0.69
Washing Detergent £6.50
Eggs £1.10

Add the prices on the receipt in the same way as the previous example.

This time you have a decimal place (.) to show fractions of one unit (a Pound £).

Remember to include the decimal point at the end of your calculation; you should have two columns to the right of it. Technically these columns are should be labelled 'Tenths' and 'Hundredths'.  However, try to add the numbers without using column headings. 

You may find it easier to write or print this example.

Your final answer should be: £17.81.

If you have arrived at a different answer then check your working and try again.

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