Y5 U5 L1

Y5 U5 L1 Algorithm

By Enes Nas

From your experience

What problem do you solve when you wash your hands? Why are the instructions below valid in exactly this order for you, your friends, or any other person?

Step 1
Wet your hands with water.
Step 2
Wash your hands with soap and water.
Step 3
Rinse your hands.
Step 4
Dry your hands with a towel, paper towel, or hand dryer.

Activity

Work in pairs. Together with a classmate, write down the steps you follow when brushing your teeth. Check what your classmate wrote and see if you both came up with the same number of steps and the same order.

Open Ended

Look up the word algorithm in the dictionary and describe the steps you followed to find its definition. How many operations did you need in order to discover the meaning of a word using the dictionary?

Algorithm

• Algorithm = sequence of steps to solve a problem.

• Examples of problems: assembling a toy, making tea, looking up a word, handwashing, solving math problems.

• Steps must be clear and limited in number.

  • Example (handwashing):

    1. Wet hands 2. Apply soap 3. Rinse 4. Dry

• In computer science, a step = operation or instruction.

• Common instructions in algorithms:

  • read = you give info to the algorithm

  • write = the algorithm gives you info

​Follow the diagram below and make a paper frog using the origami technique. Then, try to make the same toy, using the same technique, without using the diagram. In both cases, record the time it takes to complete the task.
What do you observe? In which of the two situations was the completion time shorter?

The word "algorithm" comes from the name of the Persian mathematician and astronomer Al-Khwârizmî, who lived in the 9th century.
• One of the oldest algorithms used in mathematics was invented by Eratosthenes (a Greek mathematician, astronomer, philosopher, geographer, and musician who lived between 276–195 BC) and is known as the "Sieve of Eratosthenes."

Multiple Choice

Look at the square in the image. It has a side length of a. Which of the following represents the correct algorithm to calculate the area of the square?

• 1. Read the perimeter of the square.

  2. Multiply it by 2.

  3. Write the result as the area.

• 1. Read the side length a

  2. Multiply a by 4.

  3. Write the result as the area.

• 1. Read the side length a.

  2. Multiply a × a.

  3. Write the result as the area of the square.

• • Read the diagonal of the square.

  • Multiply it by a.

  • Write the result as the area.

What steps do you take when preparing for a one-day mountain trip where meals are not provided?

Open Ended

Describe your way from home to school in steps

Draw

Describe your way from home to school

Open Ended

Write down what steps should the gardener take to reach to the flower (avoiding the tree).

Multiple Choice

The read instruction in computing means the same as what is asked in a maths problem.

• True

• False

Multiple Choice

I cannot describe an algorithm using blocks.

• True

• False

Multiple Choice

Every algorithm has 4 steps

• True

• False

Multiple Choice

An algorithm can solve a type of problem

• True

• False

code.org

Open code.org(click) and sign in with your school email. You are assigned a lesson called (Express Course) Start and work in your own pace. Ask for your teacher when need some help. You can also ask for a hint by clicking the "yellow bulb" icon.