Cupcakes and Calculations: Mastering Long Multiplication!
Lesson Description
Video Resource
Key Concepts
- Multiplication as repeated addition
- Place value (ones, tens, hundreds)
- Regrouping (carrying over)
- Placeholder zero in long multiplication
- Product as the answer to a multiplication problem
Learning Objectives
- Students will be able to multiply double-digit numbers by single-digit numbers with and without regrouping.
- Students will be able to multiply double-digit numbers by double-digit numbers using long multiplication, including the placeholder zero.
- Students will understand and apply the concept of regrouping in multiplication.
- Students will define the word 'product' and explain what it means in multiplication.
Educator Instructions
- Introduction (5 mins)
Begin by reviewing basic multiplication concepts using the cupcake examples from the video (6 x 2, 9 x 1, 3 x 5). Define the word 'product'. - Double-Digit × Single-Digit Multiplication (15 mins)
Watch the section of the video (2:55-7:17) demonstrating double-digit times single-digit multiplication (12 x 4, 21 x 3, 42 x 2). Practice a few similar problems as a class, emphasizing lining up place values. Address any questions the students might have. - Regrouping (10 mins)
Watch the section of the video (7:17-10:09) explaining regrouping (57 x 2, 47 x 3). Work through additional regrouping problems together, step-by-step. Have students explain the process in their own words. - Double-Digit × Double-Digit Multiplication (20 mins)
Watch the section of the video (10:09-19:45) covering double-digit times double-digit multiplication (21 x 11, 62 x 20, 34 x 13). Emphasize the importance of the placeholder zero. Practice problems together, and then have students work independently or in pairs. Reinforce the steps: cover the digit, placeholder zero, add them together. - Review and Wrap-up (10 mins)
Review all the steps of long multiplication. Answer any final questions. Briefly discuss how these skills apply to real-world problems. Recap the definition of 'product'.
Interactive Exercises
- Cupcake Calculation Challenge
Present word problems involving cupcakes that require long multiplication to solve. For example: 'Clancy buys 23 boxes of cupcakes, and each box contains 14 cupcakes. How many cupcakes does Clancy buy in total?' - Place Value Power-Up
Write numbers on the board and have students identify the value of each digit (e.g., In the number 34, the 3 is in the tens place, so it represents 30).
Discussion Questions
- Why is it important to line up the numbers correctly according to place value when multiplying?
- What does it mean to 'regroup' in multiplication, and why do we do it?
- Why do we use a placeholder zero when multiplying double-digit numbers by double-digit numbers?
- What is the product in a multiplication problem, and where do we find it?
Skills Developed
- Multiplication
- Problem-solving
- Critical thinking
- Attention to detail
- Place value understanding
Multiple Choice Questions
Question 1:
What is the answer to a multiplication problem called?
Correct Answer: Product
Question 2:
What do you do if the answer to multiplying the ones place is a two-digit number?
Correct Answer: Only write the ones digit and regroup the tens digit.
Question 3:
In the problem 24 x 12, what is the first step?
Correct Answer: Multiply 2 x 4
Question 4:
In long multiplication, what number do we put down as a placeholder?
Correct Answer: 0
Question 5:
What does it mean to 'regroup' in multiplication?
Correct Answer: To carry over a digit to the next place value.
Question 6:
What is 12 x 0?
Correct Answer: 0
Question 7:
What is the product of 11 x 11?
Correct Answer: 121
Question 8:
Clancy bought 4 boxes of cupcakes, with 6 cupcakes in each box. How many cupcakes did he buy?
Correct Answer: 24
Question 9:
Which place value is the farthest to the right?
Correct Answer: Ones Place
Question 10:
What two numbers do we add together after using the placeholder 0?
Correct Answer: Both multiplication problems.
Fill in the Blank Questions
Question 1:
The answer to a multiplication problem is called the ________.
Correct Answer: product
Question 2:
When we carry a number in multiplication, it's called ________.
Correct Answer: regrouping
Question 3:
When multiplying double-digit numbers, we use a __________ zero as a placeholder.
Correct Answer: zero
Question 4:
In the number 45, the 4 represents 4 ________.
Correct Answer: tens
Question 5:
When we perform long multiplication, we always start with the __________ place.
Correct Answer: ones
Question 6:
Any number times __________ equals zero.
Correct Answer: 0
Question 7:
The number behind the owl is in the __________ place.
Correct Answer: tens
Question 8:
When multiplying 34 x 13, you have to add __________ together at the end to get the product.
Correct Answer: both multiplication problems
Question 9:
If Clancy bought 5 boxes of cupcakes with 2 cupcakes in each box, the product would be __________.
Correct Answer: 10
Question 10:
The __________ is one place value larger than the ones place.
Correct Answer: tens
Educational Standards
Teaching Materials
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