Topicma33bf79c765903ac_1528449000663_0Topic

The order of operationsthe order of operationsThe order of operations

Levelma33bf79c765903ac_1528449084556_0Level

Second

Core curriculumma33bf79c765903ac_1528449076687_0Core curriculum

II. Operations on natural numbers. The student:

11) applies rules about the order of operationsthe order of operationsthe order of operations.

Timingma33bf79c765903ac_1528449068082_0Timing

45 minutes

General objectivema33bf79c765903ac_1528449523725_0General objective

Performing simple calculations in memory or more difficult operations using the long methods, and applying this skills in practical situations.

Specific objectivesma33bf79c765903ac_1528449552113_0Specific objectives

1. Formulating rules about the order of operationsthe order of operationsthe order of operations.

2. Applying rules about the order of operationsthe order of operationsthe order of operations.

3. Communicating in English, developing basic mathematical, computer and scientific competences, developing learning skills.

Learning outcomesma33bf79c765903ac_1528450430307_0Learning outcomes

The student:
1. Formulates rules about the order of operationsthe order of operationsthe order of operations.

2. Applies rules about the order of operationsthe order of operationsthe order of operations.

Methodsma33bf79c765903ac_1528449534267_0Methods

1. Situational analysis.

2. Board game.

Forms of workma33bf79c765903ac_1528449514617_0Forms of work

1. Individual work.

2. Group work.

Lesson stages

Introductionma33bf79c765903ac_1528450127855_0Introduction

Students give examples of addition, subtraction, multiplication and division of natural numbers.

Students write down the operations according to the description:

a. add the result of the multiplication of the number 3 by number 4 to the number 2,

b. add the number 2 to number 3 and multiply by 4.

Procedurema33bf79c765903ac_1528446435040_0Procedure

Discussion – students think if they obtain the same result in both cases. They propose different ways of calculations, for example ‘step by step’ or by using graphs.

After obtaining different results, they look for the causes.

They think how to write the operation using one expression.

-Different results are caused by the different order of operations.ma33bf79c765903ac_1527752263647_0Different results are caused by the different order of operations.

The teacher informs students that expressions made of numbers, signs of operations and, possibly, parentheses are called arithmetic expressions. Arithmetic is a science about numbers and operations on them.

Students work individually, using computers. They open the slideshow and observe the ‘operations car race’.

After having finished the exercise, students present the results of their observations and write down the order in which we should do the operations.

[Slideshow 1]

The conclusion students should make:

Operations should be done in the following orderma33bf79c765903ac_1527752256679_0Operations should be done in the following order

1. operations in parentheses,

2. multiplication or division – in the order it is written,

3. addition or subtraction – in the order it is written.

The teacher divides students into 5 persons groups.

The teacher distributes the board game and its rules.

Rules of the game:

1. Place your pawn on the START field.

2. Throw the dice and move as many fields as the dice showed.

3. Calculate the value of the expression on the card placed on the field you are at.

4. Check your results on the calculator, consult the doubts with the teacher.

5. If the result is correct, you stay at the field and wait for your next turn.

6. If the result is wrong, you go back to the field you were at before.

7. The person that gets first to the final field, gets the highest mark.

8. GOOD LUCK.

Exemplary board for the game.

[Table 1]

Students use obtained information in the exercises.

Task
Write down the solution of the task using one arithmetic expression. Calculate the value of this expression.
1. In a school there are two fourth grades in which there are 25 students are three fourth class in which there are 20 students. How many fourth‑graders there are in the school?

2. Tomek had 35 zł, he bought 4 bars 3 zł each and a chocolate that cost 5 zł. How many złoty did he have left after the shopping?

An extra task
Write the number 100 as the arithmetic expressionthe arithmetic expressionthe arithmetic expression, using signs of operations and parentheses and each one of the nine digits, only once.

Lesson summaryma33bf79c765903ac_1528450119332_0Lesson summary

Students do the revision exercises. Then together they sum‑up the classes, by formulating the conclusions to memorise. Operations should be done in the following order
1. operations in parentheses,

2. multiplication or division – in the order it is written,

3. addition or subtraction – in the order it is written.

Selected words and expressions used in the lesson plan

a grapha grapha graph

a paranthesisa paranthesisa paranthesis

arithmeticsarithmeticsarithmetics

the arithmetic expressionthe arithmetic expressionthe arithmetic expression

the operation in parenthesesthe operation in parenthesesthe operation in parentheses

the order of operationsthe order of operationsthe order of operations