Add and Subtract Up to 999,999

Created by Shaunak Ghosh

You will learn to neatly line up big numbers, then fluently add and subtract multi-digit whole numbers using the standard algorithm. You will also solve word problems by choosing the correct operation, setting up the problem, and checking that your answer makes sense.

Requirements

Basic place value (ones, tens, hundreds)
Addition and subtraction facts within 20
Reading multi-step sentences in word problems
Writing numbers neatly in columns

What you'll learn

I can line up whole numbers correctly through the hundred-thousands place.
I can add whole numbers using the standard algorithm, including carrying when a column sum is 10 or more.
I can solve addition word problems by choosing addition, writing an equation, and using the standard algorithm.

Learning path

7 modules • Each builds on the previous one

Line up place values correctly

Before you add or subtract, you must stack numbers so ones are under ones, tens under tens, and so on. This keeps every digit in the correct place so your answer makes sense.

1 video7 min

Add up to six digits standard

Use the standard algorithm to add whole numbers up to 999,999. Add from right to left (ones to highest place), writing each digit in the correct column.

1 video4 min

Add with regrouping (carrying)

Sometimes a column adds to 10 or more. You write the ones digit and “carry” the tens to the next column to the left.

1 video5 min

Addition word-problems up to six digits

Solve story problems that mean “put together” or “total.” First decide what the problem is asking, then add using the standard algorithm.

1 video5 min

Subtract with regrouping standard algorithm

Use the standard algorithm to subtract multi-digit numbers up to 999,999. When the top digit is smaller, regroup (borrow) from the next place to the left.

3 videos15 min

Subtract across zeros (borrow chain)

Sometimes you need to regroup across one or more zeros (like 50,002 − 1,876). You may need to “borrow” from farther left and turn zeros into 9s.

1 video6 min

Subtraction word-problems up to six digits

Solve story problems that mean “take away,” “how many left,” or “find the difference.” Decide if subtraction is needed, then subtract using the standard algorithm and check your answer.

1 video5 min

Start Learning

Begin your learning journey

Modules7

Duration44 min

Science-backed learning

In-video quizzes and scaffolded content to maximize retention.

Key concepts

Lining Up Multi-Digit Numbers By Place ValueStandard Algorithm For AdditionCarrying (Regrouping) In Addition

Loading course…

What you'll learn

I can line up whole numbers correctly through the hundred-thousands place.
I can add whole numbers using the standard algorithm, including carrying when a column sum is 10 or more.
I can solve addition word problems by choosing addition, writing an equation, and using the standard algorithm.

Learning path

7 modules • Each builds on the previous one

Line up place values correctly

Before you add or subtract, you must stack numbers so ones are under ones, tens under tens, and so on. This keeps every digit in the correct place so your answer makes sense.

1 video7 min

Add up to six digits standard

Use the standard algorithm to add whole numbers up to 999,999. Add from right to left (ones to highest place), writing each digit in the correct column.

1 video4 min

Add with regrouping (carrying)

Sometimes a column adds to 10 or more. You write the ones digit and “carry” the tens to the next column to the left.

1 video5 min

Addition word-problems up to six digits

Solve story problems that mean “put together” or “total.” First decide what the problem is asking, then add using the standard algorithm.

1 video5 min

Subtract with regrouping standard algorithm

Use the standard algorithm to subtract multi-digit numbers up to 999,999. When the top digit is smaller, regroup (borrow) from the next place to the left.

3 videos15 min

Subtract across zeros (borrow chain)

Sometimes you need to regroup across one or more zeros (like 50,002 − 1,876). You may need to “borrow” from farther left and turn zeros into 9s.

1 video6 min

Subtraction word-problems up to six digits

Solve story problems that mean “take away,” “how many left,” or “find the difference.” Decide if subtraction is needed, then subtract using the standard algorithm and check your answer.

1 video5 min