Algorithms and Pseudocodes

Students will:

1. restate/review the definition of an algorithm. Algorithm - a step by step set of directions for completing a task.

2. watch What is an Algorithm? by David J. Malan to explore a simple algorithm of counting people with a pseudocode.

3. write the pseudocodes in their journal as they are discussed in the video.

   Pseudocode 1

line 1 - let N = 0

line 2 - for each person in room (loop begins)

line 3 - Set N = N + 1

Output =

End.

Pseudocode 2

line 1 - let N = 0

line 2 - for each pair in room (loop begins)

line 3 - Set N = N + 2

Output =

End.

Pseudocode 3

line 1 - let N = 0

line 2 - for each pair in room (loop begins)

line 3 - Set N = N + 2

line 4 - If 1 person remains then (condition)

line 5 - Set N = N + 1

Output =

End.

4. edit Pseudocode 3 in their journal to create algorithms that count by 5 and 10.  

5. As a class, complete the seven THINK questions. The teacher must have a TEDEd free account to access. Project the assessment on the board for all to see or enter questions in a Google Spreadsheet for all to complete and review results.

6. explore additional examples of pseudocodes using the examples below then create their own to share with the class.

Examples:

Program adding two numbers

Input Number1

Input Number2

Number3 = Number1 + Number2

Output Number 3

End.

Program get dressed

if temperature > 75

    put_on( tshirt )

    put_on( shorts )

    put_on( sandals )

else if temperature >60

    put_on( blue_shirt )

    put_on( blue_jeans )

    put_on( white_socks )

    put_on( sneakers )

End.

Program Make a Cup of Tea

Organize everything together

Plug in kettle

Put tea bag in cup

Put water into kettle

Wait for kettle to boil

Add water to cup

Remove tea bag with spoon/fork

Add milk and/or sugar

Serve

End.

(Can you add conditions to the above program? Remember to indent)

8. In pairs, students will discuss and record answers in their journals to the question “Who can execute an algorithm more quickly, a human or a computer? How come?” Pairs will share their discussions with the class.