18
What is an algorithm?
Textbook: pp. 46–47
GoalKnow what an algorithm is and its four parts (name, start, actions, end).
New words
algorithm · algoritmcommand · buyruqstart · boshlanishiend · tugashi
Explanation
A sequence of actions carried out to reach a result is called an algorithm. Each action is written as a command. An algorithm has four parts: a name, a start, a sequence of actions and an end. An algorithm can be written in words or shown in pictures.
Worked examples
Algorithm “Washing hands”: Start. 1) Turn on the tap. 2) Wet your hands. 3) Soap them. 4) Rinse with water. 5) Dry with a towel. End.
Telling the events of a fairy tale in reverse order makes a fun riddle: from the end to the beginning.
Class activity
“Let’s build an algorithm”: together the children build the algorithm “Packing a school bag”. The teacher writes it on the board: name, start, actions, end. Then a child acts it out.
Practice
1
How many main parts does an algorithm have?
4
2
Algorithm order: 1) Dry with a towel. 2) Soap your hands. 3) Turn on the tap. Which order is right?
3, 2, 1
3
How many actions did the “Washing hands” algorithm have (example above)?
5