Add and Subtract Multi Digit

Add and Subtract
Multi-Digit

Numbers

3rd Grade

Azalea ES

Ruhlmann

Day 1:

I can estimate sums and

differences.

MA.3.NSO.2.1

Let’s review!

When we try to find the total we need to:

a) add

b) subtract

Let’s review!

When we try to find the difference we need to:

a) add

b) subtract

Vocabulary:

What does estimate mean?

An estimate is a number that is very

close to the actual answer. We can use

“friendly numbers” to help us solve!

Friendly

numbers:

Numbers that

end in 0 or 5

Vocabulary:

What does estimate mean?

• If we do not need the EXACT answer

• We need an answer quickly (using friendly

numbers)

Why do we estimate?

Steps to estimate:

Step 1: Write the problem

576 - 120 =

Step 2: Round each number to the nearest

ten or hundred.

576 - 122 =

580- 120 =

Steps to estimate:

Friendly

numbers:

Numbers that

end in 0 or 5

Step 3: Now solve the problem. This problem

wants us to SUBTRACT.

576 - 122 =

580- 120 =

Steps to estimate:

NOW YOU TRY:

Step 1: Write the problem

523 + 168=

NOW YOU TRY:

Step 2: Round each number to the nearest

ten or hundred.

523 + 168=

NOW YOU TRY:

Step 3: Now solve the problem. This problem

wants us to ADD.

523 + 168=

520 + 170 =

Day 2:

I can use addition properties to

add.

MA.3.NSO.2.1

Notes Day!

Link to

notes

Day 3:

I can decompose and use partial

sums to add.

MA.3.NSO.2.1

Vocabulary Review

What is expanded form?

Vocabulary Review

What is expanded form?

Expanded Form is when we write down the

value of each digit.

Vocabulary Review

Write this number in expanded form: 6,345

Vocabulary Review

Write this number in expanded form: 6,345

6,000 + 300 + 40 + 5

Vocabulary Review:

What does it mean to decompose?

Vocabulary Review:

What does it mean to decompose?

To decompose a number, means to break

the number apart!

How to decompose to ADD:

We have the problem

367 + 145 =

Instead of traditionally adding it up, let’s break it

down by place value to add.

How to decompose to ADD:

partial

sums

ALWAYS START

WITH THE ONES

PLACE WHEN

ADDING AND

SUBTRACTING

How to decompose to ADD:

7 + 5=

1

2

60 + 40 =

100

300 + 100 =

400

51

2

__+_______

___

Let’s try together:

ALWAYS START

WITH THE ONES

PLACE WHEN

ADDING AND

SUBTRACTING

You try on your own!

ALWAYS START

WITH THE ONES

PLACE WHEN

ADDING AND

SUBTRACTING

Day 4:

I can use an algorithm to add.

(a strategy)

MA.3.NSO.2.1

Adding Review:

Try using estimating.

634 + 155 =

Adding Review:

360 + 188 =

Try using decomposing.

ALWAYS START

WITH THE ONES

PLACE WHEN

ADDING AND

SUBTRACTING

Adding Review:

2,483 + 4,539 =

Try using decomposing.

ALWAYS START

WITH THE ONES

PLACE WHEN

ADDING AND

SUBTRACTING

Adding Review:

1,328 + 3,576=

Now try with any strategy to add.

ALWAYS START

WITH THE ONES

PLACE WHEN

ADDING AND

SUBTRACTING

Day 5:

I can use an algorithm to add with

regrouping.

MA.3.NSO.2.1

Adding Review:

Try with any strategy to add.

1,547 +

1,345=

ALWAYS START

WITH THE ONES

PLACE WHEN

ADDING AND

SUBTRACTING

Adding with Regrouping:

Adding with Regrouping:

3,529 + 2,314=

Rewrite the problem vertically

so that the numbers are lined

up according to place value.

Adding with Regrouping:

3,529

+

2,314

Let’s try together:

5,245

+

3,146

You try on your own:

2,538

+ 5,038

Day 6:

I can fluently add multi-digit

numbers.

MA.3.NSO.2.1

Let’s try together:

5,729

+

1,443

You try on your own:

4,533

+ 2,560

You try on your own:

8,125

+ 1,906

Day 7:

I can decompose to subtract.

MA.3.NSO.2.1

Review decomposing:

245

+332

200 + 40 + 5

+ 300 +30 + 2

We can decompose to subtract:

563 - 121

=

We only decompose one number.

Then, we subtract value by value.

100 + 20 + 1

563 - 100 = 463

463-20 = 443

443-1 = 442

Let’s try together:

872- 356=
We only decompose one number.

Then, we subtract value by value.

300 + 50 + 6

Let’s try another:

726 - 384=
We only decompose one number.

Then, we subtract value by value.

You try on your own:

929 - 314=
We only decompose one number.

Then, we subtract value by value.

Day 8:

I can use an algorithm to subtract.

MA.3.NSO.2.1

Subtraction song:

Use any strategy to subtract:

743 -

511=

Use any strategy to subtract:

638-

217=

Use any strategy to subtract:

748 - 432 =

Use any strategy to subtract:

1,438- 234=

Day 9:

I can use an algorithm to subtract

with regrouping.

MA.3.NSO.2.1

Subtraction song:

Using traditional subtraction:

2,874 -

1,216=

Using traditional subtraction:

814 -

375=

Using traditional subtraction:

8,394- 2,378=

Day 10:

I can fluently subtract multi-digit

numbers.

MA.3.NSO.2.1

Subtraction song:

Using traditional subtraction:

3,564 -1,927=

Using traditional subtraction:

6,283 - 4,128=

Using traditional subtraction:

8,025 -3,408=

Day 11:

I can fluently add and subtract

multi-digit numbers.

MA.3.NSO.2.1

Find the sum:

7,284 + 1,483

=

Find the sum:

3,910 + 4,583=

Find the difference:

8,037- 2,325=

Find the difference:

6,928-1,320=

Day 12:

I can solve two-step problems

using addition and subtraction.

MA.3.NSO.2.1

5

Part Part Whole

Using the bar model, what is 5 + 3?

?

3

5

Part Part Whole

Using the bar model, what is 5 + 3?

8

3

6

Part Part Whole

What number can go in the red box to make this

bar model true.

10

?

6

Part Part Whole

Write an equation with these numbers.

10

4

_______ + ________ = _________

____________ - __________ = ___________

56

Part Part Whole

Write an equation with these numbers.

189

?

_______ + ________ = _________

____________ - __________ = ___________

56

Part Part Whole

Now solve.

189

?

_______ + ________ = _________

____________ - __________ = ___________

?

?

Part Part Whole

When you see word problems, use the bar

model to help organize your work.

_______ + ________ = _________

____________ - __________ = ___________

MISSING

PART

MISSING WHOLE

Day 13:

Continued....

I can solve two-step problems

using addition and subtraction.

MA.3.NSO.2.1

?

Part Part Whole in Word Problems

MISSING

PART

The cafeteria gave out 543 cartons of

milk at breakfast and 875 cartons of milk

at lunch. The cafeteria has 2,036

Day 14: Review Day

MA.3.NSO.2.1

I can fluently add and subtract

multi-digit numbers.

Day 15: Review Day

MA.3.NSO.2.1

I can fluently add and subtract

multi-digit numbers.

Day 16: Test Day

MA.3.NSO.2.1

I can fluently add and subtract

multi-digit numbers.