Addition and subtraction

This course is a part of Arithmetic essentials, a 5-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 8 segments:

Basic addition and subtraction

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

Addition and subtraction within 20

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

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.

Multi-digit addition with regrouping

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).

Multi-digit subtraction with regrouping

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).