Topicm145cdff043b7b685_1528449000663_0Topic

Operations with integers

Levelm145cdff043b7b685_1528449084556_0Level

Second

Core curriculumm145cdff043b7b685_1528449076687_0Core curriculum

III. Integers. The student:

2) interprets the integers on the number line,

5) does the simple mental calculations with the integers.

Timingm145cdff043b7b685_1528449068082_0Timing

45 minutes

General objectivem145cdff043b7b685_1528449523725_0General objective

Reading, interpreting and processing data presented in various forms.

Specific objectivesm145cdff043b7b685_1528449552113_0Specific objectives

1. Addition, subtraction, multiplication and division of the integers.

2. Solving text tasks involving the operations with the integers.

3. Communicating in English; developing mathematical and basic scientific, technical and digital competences; developing learning skills.

Learning outcomesm145cdff043b7b685_1528450430307_0Learning outcomes

The student:

- uses the proper order of operations,

- specifies  the sign of the operations with integers without any calculations.

Methodsm145cdff043b7b685_1528449534267_0Methods

1. Learning game.

2. Situational analysis.

Forms of workm145cdff043b7b685_1528449514617_0Forms of work

1. Individual work.

2. Class work.

Lesson stages

Introductionm145cdff043b7b685_1528450127855_0Introduction

Every students brings the set of cards which he has prepared at home. On each card there is only one number: -9, -8, -7, -6, -5, -4, -3, -2, -1, 1, 2, 3,4, 5, 6, 7, 8 or 9.

The teacher introduces the topic of the lesson: developing the skills of doing operations with the integers.

First, the students discuss the operations which can be done with the natural numbers and the order of these operations. Next, they point out the operation which can be done in the set of integers , and could not be always done in a set of natural numbers.

Procedurem145cdff043b7b685_1528446435040_0Procedure

[Slideshow]

The students work individually using their computers. They are going to revise the order of the operations with the integers, in particular the specifying of the sign of the final result. 

The students work in pairs. Each student draws one card of the set of cards which were prepared for the lesson. Using the numbers they have got they do the sum, the difference, the product and the quotient (if its result is the integerintegerinteger).They compare the results and repeat the activity for few times.

The students do the operations with the integers.

Task 1

Calculate.

a) $(-4)-5:(-9)$

b) $8·(-4):16$

c) $(-10)+(-10):5$

d) $(-3)-3·(-2{)}^3$

Conclusion:

The rules involving the order of operations with the integers are the same as with natural numbers, the fractions or decimals.

Task 2

The students without any calculations identify the operations with positive result.

a) $(-3)·(-4):5·(-2)·(-4)$

b) $(-4):(-2):2·(-5)·(-6):(-4)·(-2)$

c) $(-1)·2·(-3)·4·(-5)·6·(-7)·8·9·(-10)·11$

d) $(-4):2·(-1)·3$

e) $(-4{)}^3$

Task 3

The students compare the integers filling the empty place with the sign of <, > or =.m145cdff043b7b685_1527752256679_0The students compare the integers filling the empty place with the sign of <, > or =.

a) $(-7)+(-5)·3(-36)$

b) $(-13)+(-2)+132$

c) $(-2)+(-10):(-2)3$

Task 4

The students calculate smartly the following sums:

a) $-12+7+(-8)+3+(-10)$

b) $-3+7+(-2)+(-5)+4$

c) $-4+4+18+(-13)$

d) $-67+66+(-8)+7+(-499)$

An extra task:

Among the following numbers: 5, 329, - 134, - 342, -23, - 529 choose:

a) two numbers whose product is the largest,
b) three numbers whose the product is the smallest.

Lesson summarym145cdff043b7b685_1528450119332_0Lesson summary

The students do the summarising tasks. 

Then they sum up the class drawing the conclusions to memorise:

- The rules involving the order of operations with the integers are the same as with natural numbers, the fractions or decimals.m145cdff043b7b685_1527752263647_0The rules involving the order of operations with the integers are the same as with natural numbers, the fractions or decimals.

Selected words and expressions used in the lesson plan

negative numbernegative numbernegative number

positive numberpositive numberpositive number

integerintegerinteger

division of the integersdivision of the integersdivision of the integers

addition of the integersaddition of the integersaddition of the integers

opposite numberopposite numberopposite number

multiplication of the integersmultiplication of the integersmultiplication of the integers

subtraction of the integerssubtraction of the integerssubtraction of the integers