Topicm3294bdade198496c_1528449000663_0Topic

Properties of natural numbers

Levelm3294bdade198496c_1528449084556_0Level

Second

Core curriculumm3294bdade198496c_1528449076687_0Core curriculum

I. Natural numbers in the decimal system. Student:

1) writes and reads multi‑digit natural numbers; II. Operations on natural numbers. Student:

7) recognizes numbers divisible by 2, 3, 4, 5, 9, 10, 100;

9) divides two‑digit numbers into prime factors;

13) finds the greatest common divisor (GCD) in situations not more difficult than GCD (600, 72), GCD (140, 567), GCD (10,000, 48), GCD (910, 2016) and determines the Least Common Multiple of two natural numbers with the prime factorization;

14) recognizes multiples of a given number, squares, cubes, prime numbers, composite numbers.

Timingm3294bdade198496c_1528449068082_0Timing

45 minutes

General objectivem3294bdade198496c_1528449523725_0General objective

Using simple, well‑known mathematical objects, interpreting mathematical concepts and manipulating mathematical objects.

Specific objectivesm3294bdade198496c_1528449552113_0Specific objectives

1. Consolidation of knowledge of natural numbers.

2. Consolidation of knowledge and skills regarding the divisibility of natural numbers.

3. Communicating in English, developing mathematics skills, scientific, technical and IT competences; developing learning skills.

Learning outcomesm3294bdade198496c_1528450430307_0Learning outcomes

The student:

- consolidates his/ her knowledge of natural numbers.

- consolidates his/ her knowledge and skills regarding the divisibility of natural numbers.

Methodsm3294bdade198496c_1528449534267_0Methods

1. Expert groups (tables).

2. Situational analysis.

Forms of workm3294bdade198496c_1528449514617_0Forms of work

1. Whole class.

2. Group work.

Lesson stages

Introductionm3294bdade198496c_1528450127855_0Introduction

Prior to the lesson, eight students create four expert groups and prepare information on one subject, selected from the ones provided below.

I. Ways of writing and reading numbers. Positional decimal system. Large natural numbers.

II. Properties of operations in the set of natural numbers.

III. Prime numbers and composite numbers. Features of divisibility of numbers.

IV. Prime factorization. The Greatest Common Divisor (GCD), the Least Common Multiple (LCM).

Procedurem3294bdade198496c_1528446435040_0Procedure

Students - experts present the information they have prepared. After the presentation, they answer the questions that other students may have posed and clarify their doubts.

Information that should be included in the expert group presentations.

I EXPERT GROUP

- We use Arabic numerals to create numbers nowadays: 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9.

- The number system we use at present is called the positional decimal system.

- The position of a digit in a number can be determined using the scheme below:

[table 1]

- Large numbers:

a. 1 000 000 - million

b. 1 000 000 000 - billion

c. 1 000 000 000 000 - trillion

d. 1 000 000 000 000 000 – quadrillion

e. 1 000 000 000 000 000 000 – quintillion

f. 1 000 000 000 000 000 000 000 – sextillion

II EXPERT GROUP

- Natural numbers can be added, subtracted, divided and squared or cubed.m3294bdade198496c_1527752256679_0Natural numbers can be added, subtracted, divided and squared or cubed.

- The order of performing operations:

1. operations in brackets,

2. exponentiation,

3. multiplication or division - in the order of writing,

4. addition or subtraction - in the order of writing.

- Properties of operations:

1. Addition is Associative and Commutative.

2. Multiplication is Associative and Commutative.

3. We do not divide by zero.

III EXPERT GROUP

- The prime number is a natural number greater than 1, whose only divisors are 1 and itself.m3294bdade198496c_1527752263647_0The prime number is a natural number greater than 1, whose only divisors are 1 and itself.

- A composite number is a natural number greater than 1 that has more than two divisors.

- Numbers 0 and 1 are neither prime numbers nor composite numbers.

- Features of divisibility of natural numbers. The natural number is divisible

a. by 2 if its unity digit is 0, 2, 4, 6 or 8;

b. by 3 if the sum of its digits is a number divisible by 3;

c. by 4 if its last two digits form a number divisible by 4;

d. by 5 if its unity digit is 0 or 5;

e. by 9, if the sum of its digits is a number divisible by 9;

f. by 25 if its last two digits form a number divisible by 25.

IV EXPERT GROUP

- Prime factorization is the representation of this number in the form of a product of prime numbers.

- GCD (a, b) - the greatest common divisor of natural numbers a and b, is the largest natural positive number, which is also the divisor of the number a and the divisor of the number b.

- LCM (a, b) - the least common multiple of the numbers a and b, the smallest positive natural number that is divisible by the number of a and the number of b. The teacher divides students into four groups who approach the expert stations (tables). Each of the groups solves the tasks prepared by the teacher. Experts support students, explain their doubts.

The teacher supervises the work of groups. After completing the tasks in a given scope, groups proceed to the next station.

GROUP I

Task 1
Write two numbers, in which:

a) the number of hundreds is 5,

b) the number of thousands is 3,

c) the number of tens of thousands is 7,

Task 2
Enter each number into the table and then provide their word names.

a) 5,254, 236

b) 124 509 843 548

c) 78 590 452 153 624 752

[table 2]

GROUP II

Task 1
Not doing any calculations, compare the values of the arithmetic expressions. Put in the blank space the appropriate symbols <,> or = .

a) 354 + 2541 ________ 2541 + 354

b) 368 + (3659 + 1452)________ (368 + 1452) + 3659

c) 325 · 254 - 254 ________ 254 · 325 - 325

Task 2
Calculate, remembering the order of operationsorder of operationsorder of operations:

a) 13Indeks górny 2 - 12Indeks górny 2

b) 5891 – 4716 : 9

c) (4125 + 275) : 25 - 12

GROUP III

Task 1
Write two prime numbers not greater than 60, which fulfill the condition:

a) the sum of the numbers is a prime numberprime numberprime number,

b) the difference between numbers is the prime numberprime numberprime number.

Task 2
Open the applet. Using the features of divisibility, put the numbers in the right places.

[Geogebra applet 1]

GROUP IV

Task 1
Distribute into the factors the following numbers 420 and 525, then calculate GCD (420, 525) and LCM (420, 525).

Task 2
Solve the word problem. Write down the solution. Zosia equally divided 48 chocolate candies, 30 jellies and 12 fruit candies between her friends. How many friends received sweets from Zosia? How many candies did everyone get?

The teacher summarizes and evaluates students’ work and explains all the doubts.

An extra task:
In the blank space write the number so that the number obtained is divisible by 18. 25 ____458 ____ 42

Lesson summarym3294bdade198496c_1528450119332_0Lesson summary

Students do the revision exercises.

They formulate conclusions to remember:

- We use Arabic numerals to create numbers nowadays: 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9.

- The number system we use at present is called the positional decimal system.

- Natural numbers can be added, subtracted, divided and squared or cubed.

- The order of performing operations:

1. operations in brackets,

2. exponentiation,

3. multiplication or division - in the order of writing,

4. addition or subtraction - in the order of writing.

- Addition and Multiplication are  Associative and Commutative.

- We do not divide by zero.

- The prime numberprime numberprime number is a natural number greater than 1, whose only divisors are 1 and itself.

- A composite number is a natural number greater than 1 that has more than two divisors.

- GCD (a, b) - the greatest common divisor of natural numbers a and b, is the largest natural positive number, which is also the divisor of the number a and the divisor of the number b.

- LCM (a, b) - the least common multiple of the numbers a and b, the smallest positive natural number that is divisible by the number of a and the number of b.

Selected words and expressions used in the lesson plan

associative property of additionassociative property of additionassociative property of addition

associative property of multiplicationassociative property of multiplicationassociative property of multiplication

commutative property of additioncommutative property of additioncommutative property of addition

commutative property of multiplicationcommutative property of multiplicationcommutative property of multiplication

composite numberscomposite numberscomposite numbers

decimal systemdecimal systemdecimal system

greatest common divisor of natural numbers a and bgreatest common divisor of natural numbers a and bgreatest common divisor of natural numbers a and b

least common multiple of numbers a and b,least common multiple of numbers a and bleast common multiple of numbers a and b,

order of operationsorder of operationsorder of operations

prime numberprime numberprime number

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order of operations1
order of operations

kolejność wykonywania działań

R1JMTBxr4dxko1
wymowa w języku angielskim: the order of operations
prime number1
prime number

liczba pierwsza

RH9euSfp5ldEr1
wymowa w języku angielskim: prime number
associative property of addition1
associative property of addition

łączność dodawania

R1VBiHjAUyY5T1
wymowa w języku angielskim: associative property of addition
associative property of multiplication1
associative property of multiplication

łączność mnożenia

R1Oz4ae54zUOa1
wymowa w języku angielskim: associative property of multiplication
commutative property of addition1
commutative property of addition

przemienność dodawania

Rj6fQd1c4cDdB1
wymowa w języku angielskim: commutative property of addition
commutative property of multiplication1
commutative property of multiplication

przemienność mnożenia

R15IQH1Lusddq1
wymowa w języku angielskim: commutative property of multiplication
composite numbers1
composite numbers

liczby złożone

R11ZkHPiCK40P1
wymowa w języku angielskim: composite numbers
decimal system1
decimal system

system dziesiątkowy

RUAHlbNtPAQNU1
wymowa w języku angielskim: decimal system
greatest common divisor of natural numbers a and b1
greatest common divisor of natural numbers a and b

największy wspólny dzielnik liczb naturalnych a i b

Rh6Pzl1VcnLVX1
wymowa w języku angielskim: greatest common divisor of natural numbers a and b
least common multiple of numbers a and b1
least common multiple of numbers a and b

najmniejsza wspólna wielokrotność liczb a i b

R19VAOZ9HNmfR1
wymowa w języku angielskim: least common multiple of numbers a and b