Part-Part-Whole Puzzles: Unlocking Unknown Addends!

Mathematics Grades 2nd Grade 7:28 Video
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Lesson Description

Learn how to use subtraction to find the missing part in addition problems within 20 using the part-part-whole model.

Video Resource

Addition and Subtraction Within 20 | Subtracting to Find the Unknown Added | Kids Academy

Kids Academy

Duration: 7:28
Watch on YouTube

Key Concepts

  • Part-Part-Whole Model
  • Inverse Relationship of Addition and Subtraction
  • Finding the Unknown Addend

Learning Objectives

  • Students will be able to identify the 'whole' and 'part' in a given addition problem.
  • Students will be able to use subtraction to find the missing 'part' in a part-part-whole model.
  • Students will be able to verify their answer by adding the two 'parts' to ensure they equal the 'whole'.

Educator Instructions

  • Introduction (5 mins)
    Begin by reviewing the concepts of addition and subtraction. Introduce the 'part-part-whole' model as a way to visualize addition problems. Explain that the 'whole' is the total and the 'parts' are the numbers that add up to the total. Show visual examples using objects like blocks or counters.
  • Video Viewing (7 mins)
    Play the Kids Academy video "Addition and Subtraction Within 20 | Subtracting to Find the Unknown Added | Kids Academy." Encourage students to pay attention to how the video uses subtraction to find the missing part.
  • Guided Practice (10 mins)
    Work through several examples of part-part-whole problems as a class. Use manipulatives (like counters or drawings) to represent the 'whole' and the known 'part'. Demonstrate how to subtract the known 'part' from the 'whole' to find the missing 'part'. Encourage students to explain their thinking process.
  • Independent Practice (10 mins)
    Provide students with a worksheet containing part-part-whole problems. Have them solve for the missing part using subtraction. Encourage them to check their answers by adding the two parts together. Walk around the classroom to offer assistance and answer questions.
  • Wrap-up (3 mins)
    Review the key concepts of the lesson. Ask students to share what they learned and how they can use subtraction to solve addition problems. Reinforce the importance of checking their work.

Interactive Exercises

  • Missing Number Card Game
    Create cards with part-part-whole problems, leaving one of the parts blank. Divide students into pairs and have them take turns finding the missing numbers using subtraction and addition.
  • Drawing Part-Part-Whole
    Have students draw their own part-part-whole models with pictures to represent different numbers. Then have them create a number sentence to match their picture.

Discussion Questions

  • What is the 'whole' in a part-part-whole problem?
  • How can subtraction help us find a missing part?
  • Why is it important to check our work when solving math problems?

Skills Developed

  • Subtraction
  • Problem-Solving
  • Critical Thinking
  • Visual Representation

Multiple Choice Questions

Question 1:

In a part-part-whole problem, what is the 'whole'?

Correct Answer: The biggest number

Question 2:

What operation do we use to find a missing part?

Correct Answer: Subtraction

Question 3:

If the whole is 10 and one part is 3, what is the other part?

Correct Answer: 7

Question 4:

To check your answer in a part-part-whole problem, you should:

Correct Answer: Add the parts

Question 5:

What is the missing part? Whole: 15, Part: 5, Missing Part: ?

Correct Answer: 10

Question 6:

Which number sentence shows how to find the missing part if the whole is 8 and one part is 2?

Correct Answer: 8 - 2 = ?

Question 7:

If you know both parts, how do you find the whole?

Correct Answer: Add them together

Question 8:

The whole is 12. One part is 4. What's the missing part?

Correct Answer: 8

Question 9:

What is the missing part? Whole: 9, Part: 1, Missing Part: ?

Correct Answer: 8

Question 10:

In a part-part-whole model, the parts are 6 and 4. What is the whole?

Correct Answer: 10

Fill in the Blank Questions

Question 1:

The biggest number in a part-part-whole problem is called the ________.

Correct Answer: whole

Question 2:

To find the missing part, you need to _________ the known part from the whole.

Correct Answer: subtract

Question 3:

If the whole is 11 and one part is 5, the other part is _________.

Correct Answer: 6

Question 4:

Adding the two parts together should equal the _________.

Correct Answer: whole

Question 5:

If you have two parts, 7 and 2, you can _____ them together to find the whole, which is 9.

Correct Answer: add

Question 6:

When you subtract, you are taking ______ from a number.

Correct Answer: away

Question 7:

The whole is 14, and one part is 6. To find the missing part, you would do 14 ______ 6.

Correct Answer: minus

Question 8:

If you add the parts and the answer is not the whole, then something is ________.

Correct Answer: wrong

Question 9:

In the part-part-whole model, you are looking for the missing ______.

Correct Answer: part

Question 10:

The whole is 20, one part is 10, so the other part is ______.

Correct Answer: 10

Educational Standards

2.N.2.1:Use the relationship between addition and subtraction to generate basic facts with sums and minuends of up to 20. 2.N.2.2:Demonstrate fluency with basic facts of addition and subtraction with sums and minuends of up to 20. 2.A.2.3:Apply the commutative property, identity property, and number sense to find values for unknowns that make addition and subtraction number sentences true or false.

Teaching Materials

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