Scratch in the classroom (Basic Mathematical Operations)

Primary 6 Second Term Lesson Notes – Week 9

Subject: Computer Studies
Class: Primary 6
Term: Second Term
Week: 9
Topic: Scratch in the Classroom – Basic Mathematical Operations

Behavioral Objectives

By the end of this lesson, pupils should be able to:

1. Explain the concept of mathematical operations in Scratch.
2. Use Scratch blocks to perform basic mathematical operations (addition, subtraction, multiplication, and division).
3. Create a simple project using Scratch to perform calculations.
4. Understand how to use the operator blocks in Scratch for solving math problems.

Keywords

• Scratch
• Operators
• Addition
• Subtraction
• Multiplication
• Division
• Blocks
• Calculation

Set Induction

The teacher will introduce the lesson by asking pupils if they know how to use Scratch for calculations. The teacher will display a simple project where Scratch is used to add two numbers and ask pupils if they can guess how it works.

Entry Behavior

Pupils have experience using Scratch to draw shapes and animate objects. They are familiar with basic mathematical operations such as addition, subtraction, multiplication, and division.

Learning Resources and Materials

• Computer systems with Scratch installed
• Projector (optional)
• Worksheet with instructions on creating a Scratch project for basic math operations
• Example Scratch project demonstrating basic operations

Building Background/Connection to Prior Knowledge

Pupils are familiar with basic math operations (addition, subtraction, multiplication, and division) and have learned how to use Scratch for creating shapes. This lesson will build on their knowledge by integrating math with coding.

Embedded Core Skills

• Problem-solving
• Logical thinking
• Creativity
• Technology skills
• Analytical thinking

Instructional Materials

1. Scratch software interface
2. Example of a simple Scratch project performing a math operation
3. Worksheet with math problems to be solved using Scratch

Lesson Content

What are Mathematical Operations in Scratch?

Mathematical operations in Scratch refer to the ability to use Scratch’s operator blocks to perform calculations like addition, subtraction, multiplication, and division. These blocks can take numbers as inputs and produce results.

Operator Blocks in Scratch

1. Addition: Use the “+” block to add two numbers.
   Example:
   scss

   Copy code

   (5 + 3) = 8

2. Subtraction: Use the “-” block to subtract one number from another.
   Example:
   scss

   Copy code

   (9 - 4) = 5

3. Multiplication: Use the “×” block to multiply two numbers.
   Example:
   scss

   Copy code

   (6 × 2) = 12

4. Division: Use the “÷” block to divide one number by another.
   Example:
   scss

   Copy code

   (12 ÷ 3) = 4


Steps to Perform Basic Math Operations in Scratch

1. Open Scratch and create a new project.
2. Select a sprite to perform the calculations (e.g., the cat sprite).
3. Add the Operators extension to your Scratch project.
4. Use the operator blocks to perform basic math operations:
   • Drag the “+”, “-”, “×”, or “÷” blocks from the operator category into the scripts area.
   • Place numbers or variables into the blocks to perform calculations.
5. Display the result of the calculation using the “say” block, so the sprite announces the answer.

Example of a Simple Addition Project

• Open Scratch and create a new project.
• Use the following code to make the sprite add two numbers and announce the result:

  Code:

  sql

  Copy code

  When Green Flag clicked
Say (join [5] [ + 3])
Say (join [result of (5 + 3)])


Example of a Simple Multiplication Project

• Make the sprite multiply two numbers and announce the result:

  Code:

  sql

  Copy code

  When Green Flag clicked
Say (join [6] [ × 2])
Say (join [result of (6 × 2)])


Teacher’s Activities

1. Introduce the topic by explaining how Scratch can be used to perform basic mathematical operations.
2. Show the pupils how to add the operator blocks and use them in Scratch.
3. Demonstrate a simple addition project, where the sprite announces the result of a math operation.
4. Encourage pupils to create their own Scratch projects to perform basic operations.
5. Walk around the class and assist students with coding their projects.

Learners’ Activities

1. Open Scratch and follow the teacher’s demonstration.
2. Create a project that performs a basic math operation (addition, subtraction, multiplication, or division).
3. Use the “say” block to display the result of the calculation.
4. Share their projects with the class and explain how they performed the operations.

Evaluation Questions

Part A: Objective Questions

1. The block used for addition in Scratch is called the _______ block.
   a) +
   b) –
   c) ×
   d) ÷
   Answer: a) +
2. The operator block used for subtraction in Scratch is _______.
   a) +
   b) –
   c) ×
   d) ÷
   Answer: b) –
3. Which operator block is used to perform division in Scratch?
   a) ÷
   b) ×
   c) +
   d) –
   Answer: a) ÷
4. Which block displays the result of a calculation in Scratch?
   a) Speak
   b) Say
   c) Show
   d) Tell
   Answer: b) Say
5. The operator block for multiplication in Scratch is _______.
   a) +
   b) ÷
   c) ×
   d) –
   Answer: c) ×

Part B: Theory Questions

1. How do you perform addition in Scratch?
2. Explain the function of the operator blocks in Scratch.
3. Write the Scratch code to multiply 4 by 5 and display the result.
4. How can Scratch be used to perform division?
5. What is the role of the “say” block in a Scratch project?

Part C: True or False Questions

1. The operator blocks in Scratch are used to perform basic mathematical operations.
   True
2. The “say” block is used to perform calculations in Scratch.
   False
3. Scratch cannot perform mathematical operations like addition or subtraction.
   False
4. The “÷” block is used for division in Scratch.
   True
5. The operator blocks only work with numbers, not variables.
   False

Part D: Fill-in-the-Gaps Questions

1. The block used for multiplication in Scratch is _______.
   Answer: ×
2. To perform addition in Scratch, you use the _______ block.
   Answer: +
3. The _______ block allows the sprite to display the result of a calculation.
   Answer: Say
4. To perform division in Scratch, you use the _______ block.
   Answer: ÷
5. The block used for subtraction in Scratch is _______.
   Answer: –

Conclusion

The teacher will review the Scratch projects created by pupils, ensuring that they understand how to use the operator blocks for mathematical operations. Pupils will be encouraged to experiment with more complex operations in Scratch.