Subtraction: 4-digit

Lesson Plan - Get It!

Audio:

Subtracting large numbers can seem impossible, but is it really that different from other subtraction problems?

Share with your parent or teacher what you know about subtracting numbers.

Did you remember these important rules?

1. Align the digits by place value and decimal points if there is one.
2. Order matters! The greater number should be the starting number or top number if it is written vertically.
3. Regroup if needed.
4. "Add up" to check your answer. The bottom two numbers added together should give you the starting number.

For example, 15 - 8 = 7, so if we check, 7 + 8 = 15.

Before going on, review regrouping with Go Next Door (Subtraction with Regrouping song) by EDROCKER:

After the video, discuss with a parent or teacher:

• How is four-digit subtraction different from two- and three-digit subtraction? How is it the same?
• How can you figure out which number is the greater number?

To subtract whole numbers:

1. Rewrite the problem vertically and line up the place values and decimal points. Be sure the greater number is the top number.
2. Begin in the ones place and subtract. Regroup if needed.
3. Move to the left and subtract the tens, hundreds, and thousands.
4. Check your work by "Adding up." Add the two bottom numbers to be sure the sum equals the top number.

$2,504 - $1,162 =

Rewrite the problem, with the greater number on top:

Subtract and regroup as needed, starting in the ones place:

"Add up" and check your work. $2,504 is the number we started with, so we are correct!

Discuss with a parent or teacher how to check a subtraction problem. How are addition and subtraction related?

In the Got It? section, you will practice four-digit subtraction with games!