mathematics

Review of expanded form and regrouping

Created by: Tamara V. Russell

Lesson Objective

Today we will see if you remember how to use expanded form as a strategy

for addition.

Essential question

How do you break apart addends to add thousands, hundreds, tens and

then ones?

vocabulary

• value – this is what a digit is worth based on its place within a number.

• expanded form – a way to write a number that shows the values of each digit of a number.

reviewWhat is the value of the underlined

digit?

33

reviewWhat is the value of the underlined

digit?

755

reviewWhat is the value of the underlined

digit?

475400

reviewWhat is the value of the underlined

digit?

19,98510,000

Expanded form

• Now let’s review writing numbers in expanded form.

• Here is an example…

395 = 300 + 90 + 5

review

• How do you write 281 in expanded form?

281 = 200 + 80 + 1

review

• How do you write 3,561 in expanded form?

3,561 = 3,000 + 500 + 60 + 1

review

• How do you write 8,309 in expanded form?

8,309 = 8,000 + 300 + 9

review

• How do you write 45,897 in expanded form?

45,897 = 40,000 + 5,000 + 800 + 90 + 7

Lesson

• You can use expanded form as a strategy to add numbers.

• For example…

375 = 300 + 70 + 5123 = 100 + 20 + 2497 = 400 + 90 + 7

Practice

• Can you complete the following problem?

412= 400 + 10 + 2281= 200 + 80 + 1_____________________

_____ __________

+

693 = 600 + 90 + 3

Practice

• Can you complete the following problem?

223= 200 + 20 + 3156= 100 + 50 + 6_____________________

_____ __________

+

379 = 300 + 70 + 9

Practice

• Can you complete the following problem?

560= 500 + 60 + 0419= 400 + 10 + 9_____________________

_____ __________

+

693 = 900 + 70 + 9

practice

Time for think, pair, share. First, complete lesson 7.1 on paper. Then work with a partner to share &

check your work.

regrouping

• Sometimes you will need to regroup in order to add. You can still use the expanded form strategy.

• For example…

235 = 200 + 30 + 5135 = 100 + 30 + 5370 = 300 + 60 + 10

Take away a ten and then add ten

to the tens’ column

Ten plus 60 is?

70

10

regrouping

• Let’s try that again….

235 = 200 + 30 + 5146 = 100 + 40 + 6381 = 300 + 70+ 11

Take away a ten and add ten to

the tens’ column

Ten plus 70 is?

80

10

1The answer

is….

regrouping

• One more time…

425 = 400 + 20 + 5198 = 100 + 90 + 8623 = 500 + 110+ 13

Take away a ten and add ten to

the tens’ column

Ten plus 110 is?

20

10

3The answer

is….

Take away a hundred and add a

hundred to the hundreds’ column.

100

600

White board practice

Use your whiteboards and markers for the next three

problems.

practice

Using the expanded form method, solve the following problem.

421 + 329=

practice

Using the expanded form method, solve the following problem.

531 + 396=

practice

Using the expanded form method, solve the following problem.

1,348 + 529=

Great Job!

Exit ticket: How do you break apart addends to add thousands, hundreds, tens and then ones? Respond on your

white board.