Represent and Solve One-Step Subtraction Problems w/ regrouping

Let’s Learn!

I can estimate, represent and solve math stories
involving addition and subtraction.

Created by HISD Curriculum using Google® Slides and Microsoft ® PowerPoint

Let’s review our vocabulary:

Images by HISD Curriculum using Microsoft® Word

Images by HISD Curriculum using Microsoft® Word

Created by HISD Curriculum using Google® Slides and Microsoft ® PowerPoint

Images by HISD Curriculum using Microsoft® Word

Images by HISD Curriculum using Microsoft® Word

Match

Match the following

• Equation

• Unknown term

• Estimate

• Round

A number sentence that includes an equal sign.

The missing quantity in a number sentence

An approximate number close to the exact number

A way to estimate a number to a given place value

• A number sentence that includes an equal sign.

• The missing quantity in a number sentence

• An approximate number close to the exact number

• A way to estimate a number to a given place value

●Read the story the first time.
What is this story about?

●Read the story a second time.
What is the question asking me
to find out?

●Read the story a third time.
What do I know?
What do I need to know?

Let’s review a strategy that helps us solve math
stories.

Created by HISD Curriculum using Google® Slides and Microsoft ® PowerPoint

Image reated by HISD Curriculum. Picture taken using Apple® iPhone.

Reorder

Put the 3 reads strategy in the correct order.

• What is the story about?

• What is the question asking me to find out?

• What do I know?

  What do I need to know?

1

2

3

• 1
• 2
• 3

Read the following math story.

Tara saved $297. Elizabeth saved $188.
How many more dollars did Tara save than Elizabeth?

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Use the 3-Reads strategy to comprehend the story.

What do the numbers in the story tell us?

What do we know?

What do we need to find out?

Tara saved $297.

How much more money Tara saved?

Elizabeth saved $188.

Created by HISD Curriculum using Google® Slides and Microsoft ® PowerPoint

Tara saved $ __ more than Elizabeth.

​There is a difference between the two quantities.

Tara saved more because 297 is greater than 188.

Elizabeth saved less because 188 is less than 297.

How can we represent this story using a strip diagram?

Created by HISD Curriculum using Google® Slides and Microsoft ® PowerPoint

Difference between

the two amounts

Amount Tara Saved

Amount Elizabeth Saved
?

297

188

I know Tara saved more

I know Elizabeth saved less

Tara saved $ __ more than Elizabeth.

Draw

Draw a strip diagram to represent the problem.

Multiple Choice

Which expression could we use to solve this problem?

• 297 + 188

• 297 - 188

• 297 x 188

• 297 ÷ 188

How can we represent this story using a number sentence?

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297 – 188 = ?

To find out how many more dollars Tara saved, we can
subtract the two amounts to find the difference.

Difference between

the two amounts

Amount Tara Saved

Amount Elizabeth Saved
?

297

188

Let’s round 297 and 188 to the nearest 100.

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I know that 297 is close to 300.I know that 188 is close to 200.

297 – 188 = ?

Now we know that the solution to the number story will be
about $100.

What strategy can we use to find the unknown in our original
equation?

297 – 188 = ?

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Let’s use place value to help us subtract.

Let’s represent 297 using base-ten blocks.

297 – 188 = ?

Derivative image created by HISD Curriculum using 1, 2, 3 Math Fonts with permission

188

100

80

8

Let’s decompose 188 based on place value.

Now let’s decompose 188 by place value.

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297 – 188 = ?

I see 188 has 1 hundred.

I can subtract 100.

188

100

80

8

Derivative image created by HISD Curriculum using 1, 2, 3 Math Fonts with permission

Created by HISD Curriculum using Google® Slides and Microsoft ® PowerPoint

Let’s look at the tens place.

188 has 8 tens.

297 – 188 = ?

I can subtract 80.
188

100

80

8

Derivative image created by HISD Curriculum using 1, 2, 3 Math Fonts with permission

Created by HISD Curriculum using Google® Slides and Microsoft ® PowerPoint

Let’s look at the one place.

188 has 8 ones.

297 – 188 = ?

I can subtract 8.

We have 1 hundred and 9 ones left.

109

188

100

80

8

Derivative image created by HISD Curriculum using 1, 2, 3 Math Fonts with permission

Fill in the Blank

Tara saved $297. Elizabeth saved $188. How many more dollars did Tara save than Elizabeth?

Let’s re-write the equation and complete the sentence frame.

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Tara saved $109 more than Elizabeth.

297 – 188 = 109

How do I know if my answer is reasonable?

I know I have to find the difference between the 2 numbers.

297 – 188 = 109

When I add 188 and 109, I obtain a sum of 297. This tells me that I subtracted
correctly.

I estimated that the solution was about $100. My answer, 109, is close to my estimate.

Your Turn!

Go to the “Let’s Practice” next.

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Multiple Choice

There are two lions at a zoo. The weight of the younger lion is 379 pounds. The weight of the older lion is 514 pounds.

What is the difference between these two weights?

• 235 lb

• 135 lb

• 265 lb

• 893 lb