Scratch+2

=Scratch Programming= Click the image for the program to use for homework....

Lesson Objectives

 * Know what is meant by the terms ‘Algorithm’ and ‘Stepwise Refinement.
 * Understand how we can describe problems using algorithms and stepwise refinement.
 * Use stepwise refinement to write algorithms to simple and computer based problems.

Starter (5 mins)
While on Safari in the wild jungles of Africa, Professor Claudia woke one morning and felt something in the pocket of her pyjamas. It had a head and a tail, but no legs. When Claudia got up she could feel it move inside of her pocket. However, Claudia showed little concern and went about her morning activities.

Why wasn't she concerned?

Task (groups 5 minutes)
You need to get from home to school, first thing on Monday morning. Write down the basic tasks (steps), you need to get there. 1. Wake up 2… … We will review in 3 minutes…

Task (10 mins)
In pairs, have a go at defining this problem. Using stepwise refinement, write an algorithm.

HINT: Start at layer 0. Then break down from there.

“Thomas requires a cup of milky tea with two sugars brought to him on a tray in his living room, placing on the table. Everything needed is in the kitchen. Sugar and teabags are in jars on the worktop.

Task (10 mins)
Write an algorithm for the problem assigned to your group. After 7 minutes have passed, you will review it with your ‘review group.

PROBLEM 1: Adding a friend on a social network. PROBLEM 2: Updating an MP3 player with a new album on PROBLEM 3: Buying something from an online auction site. PROBLEM 4: Booking a concert ticket online (best seats).

Class Questions..... (10 mins)
What is an algorithm? What is stepwise refinement? Why do we use algorithms in computer programming? Why is it important to use stepwise refinement in programming?

Plenary (5 mins)
We need to get to St. James’s Park from Conyers, leaving from Darlington Station, Arriving at Kings Cross St. Pancras.

What are the major and minor steps involved?