Conditional Statements/Loops

Scratch is a visual programming language that uses color-coded blocks to teach coding concepts. Below is a comprehensive guide on conditional statements (decision-making) and loops (repetition) in Scratch.

          "Programming isn’t about what you know; it’s about what you can figure out."

Pre requisite Knowledge

• Basic understanding of block-based coding platforms like Scratch or PictoBlox.
• Ability to drag and connect coding blocks correctly.
• Familiarity with simple motion and event blocks (like "move" or "when clicked").
• Understanding of variables and basic input/output blocks.
• Logical thinking to predict outcomes of given block sequences.
• Have basic experience with the [Make Code / Scratch / PictoBlox / Teachable Machine] interface. (Adjust based on topic)

Learning Objectives

1. Basic Scratch knowledge (using motion, looks, and event blocks).
2. Sample projects and visual aids to demonstrate conditionals and loops.
3. Teacher guidance with step-by-step instructions and hands-on activities.

What are Conditional statements?

In Scratch, a conditional statement is a block that allows the program to make decisions based on whether a condition is true or false. It helps control the flow of the program by executing certain blocks only if specific conditions are met.

Types of Conditional statements-

A. The If Block (Single Condition)

Purpose: Runs code only if a condition is true.

B. if () then ... else

• Executes one block of code if the condition is true, and a different block if it's false.
• Found in: Control category.

C. Nested condition

A nested condition in Scratch means placing one conditional block inside another. This allows the program to check multiple conditions in a specific order, enabling more precise control over decision-making.

Example of Conditional Statements -

Activity-Display messages using conditional statement-

What is Loops?

In Scratch, loops are control blocks that allow you to repeat a set of instructions, making your code more efficient and dynamic. 

Types of Loops-

In Scratch, loops are used to repeat actions. There are three main types of loops:

1. Forever Loop 

The forever loop is a control block in Scratch that repeats the enclosed code endlessly until the program is stopped manually.

2.Repeat Block 

The repeat (n) block in Scratch is a loop that repeats the code inside it a specific number of times.

3.Repeat Until Block 

The repeat until <condition> block is a loop that continues to repeat the enclosed code until the condition becomes true.

• The loop stops when the condition becomes true.
• If the condition is already true at the start, the loop doesn’t run at all.

Example of loops -

Activity- Change the color and costume of sprite 10 times -

Conclusion-

• Conditionals (if, if-else) → Make decisions in code.
• Loops (forever, repeat, repeat until) → Repeat actions efficiently.
• Combine them to create games, quizzes, and animations in Scratch!

Observation-

1.Comprehension of Conditional Statements

Real-World Connections: Students often relate conditional statements to everyday decisions, such as "If it's raining, then take an umbrella." This analogy helps them understand the if-then logic in programming.

Simplified Syntax: Using block-based programming platforms like Scratch allows students to grasp conditionals without the complexity of syntax, focusing instead on the logic flow.

2. Understanding Loops

• Repetition Recognition: Students recognize loops as a way to repeat actions, akin to daily routines (e.g., brushing teeth every morning).
• Visual Aids: Visual representations of loops, such as flowcharts or animations, aid in understanding the concept of iteration.

3. Common Challenges

Nested Structures: Students may struggle with nested conditionals or loops, finding it difficult to track the flow of logic.

​