Addition and subtraction

This course is a part of Arithmetic, a 6-course Topic series from Khan Academy.

In this topic, we will add and subtract whole numbers. The topic starts with 1+1=2 and goes through adding and subtracting within 1000. We will cover regrouping, borrowing, and word problems.

This course contains 19 segments:

Basic addition and subtraction

Adding and subtracting is the basis of all mathematics. This tutorial introduces you to one-digit addition and subtraction.

Making 10

Learn how to make the number 10 from two smaller numbers.

Addition and subtraction word problems within 10

Learn how to solve addition and subtraction word problems with small numbers. Numbers used are 10 or less.

Addition and subtraction within 20

Add and subtract numbers 20 or less. Find the missing number in addition and subtraction equations.

Word problems within 20

Learn how to solve addition and subtraction word problems. Numbers used are 20 or less.

Word problems with "more" and "fewer"

Learn how to solve word problems that use the words "more" and "fewer". Numbers used are 20 or less.

Intro to addition with 2-digit numbers

Learn how to add two-digit numbers. By the end of this tutorial, you'll be able to solve problems like 48+6 and 48+21. More advanced problems like 48+28 will be covered in a future tutorial.

Intro to subtraction with 2-digit numbers

Learn how to subtract two-digit numbers. By the end of this tutorial, you'll be able to solve problems like 48-9 and 48-31. More advanced problems like 48-29 will be covered in a future tutorial.

Strategies for adding and subtracting within 100

Learn strategies for adding and subtracting 2-digit numbers.

Addition within 100

Learn to add two-digit numbers like 37 and 49.

Subtraction within 100

Learn to subtract two-digit numbers like 47 and 39.

Word problems within 100

Learn how to solve addition and subtraction word problems. Numbers used 100 or less.

Adding 1s, 10s, and 100s

Learn how to solve addition problems by adding ones, tens, and hundreds.

Subtracting 1s, 10s, and 100s

Learn how to solve addition problems by adding ones, tens, and hundreds.

Strategies for adding 2- and 3-digit numbers

Learn strategies for solving addition problems within 1000.

Addition with regrouping within 1000

Learn how to add numbers like 259 + 363. These addition problems are a harder than the ones we've done before because they require regrouping (also called carrying).

Subtraction with regrouping within 1000

Learn how to subtract numbers like 363 - 259. These subtraction problems are a harder than the ones we've done before because they require regrouping (also called borrowing).

Addition and subtraction missing value problems

Learn how to solve problems like "___ - 237 = 448" where you don't know one of the values in an addition or subtraction equation.

Addition and subtraction greater than 1000

Learn strategies for adding and subtracting numbers greater than 1000.