Y4 Unit 6 (Part 2)

Unit 6:
Be a Musician (Part 2)

By Jolanda Edmond

Learning objectives

1. to predict the outcome of algorithms that contain repetition.

2. to compare and contrast algorithms designed for the same task

3. to develop programs with iteration

Multiple Select

What are the two types of loop that we have learned?

• Forever

• If...then...

• Repeat...until...

• Repeat

Let's sing a song

Twinkle, twinkle, little star
Twinkle, twinkle, little star
Twinkle, twinkle, little star

Let's sing a song

Twinkle, twinkle, little star
Twinkle, twinkle, little star
Twinkle, twinkle, little star

​Sing until I raise my hand to stop

Why did you stop singing at the second sentence?

Why did you stop singing after the third sentence?

Ask yourself

Why did you stop singing after the third sentence?

Ask yourself

​Count control:
you asked to stop after we repeated the sentence three times

Why did you stop singing at the second sentence?

Ask yourself

​A condition was met:
you raised your hand

What is iteration?

Iteration means repeating the same block of code over and over again multiple times.

Types:
1. Count-controlled loop - you learnt in Unit 4
2. Condition-controlled loop

Multiple Choice

What is iteration?

• repeating the same block of code only one time

• repeating the same block of code over and over again multiple times.

• repeating the different block of code over and over again multiple times.

• not repeating any block of code.

Multiple Select

What are the two types of iteration?

• Forever loop

• Repeat loop

• Condition-controlled loop

• Count-controlled loop

Condition-controlled loop:
repeat blocks of code until a condition is met

Count-controlled loop: repeat blocks of code a set number of times

Types of iteration

Multiple Choice

What is the main purpose of a count-controlled loop in programming?

• To run code only when a condition is true.

• To repeat blocks of code a set number of time.

• To run code forever without stopping.

• To check if user input is valid

Multiple Choice

What is the main purpose of a condition-controlled loop in programming?

• To repeat blocks of code until a condition is met.

• To store multiple values in a single variable.

• To repeat blocks of code a set number of times.

• To check syntax errors in a program.

Multiple Choice

What block do we use for condition-controlled loop?

Algorithm using iteration

Algorithm using iteration

Practise

Practise

Practise

Go further

​When the 'w' key is pressed, the volume is set to 40% and Drums Tabla plays the Le Geh Tabla sound, the Hi Na Tabla, waits one second and then plays the Hi Tun Tabla sound.

The three sounds are then repeated with the volume increasing by 5 each time until the down arrow is pressed.

Go further

ITERATION