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[Description]
Lesson description
Teacher gives the goals of the lesson.
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| 2. |
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[Description]
A factor of a number
Teacher asks the students what a factor of a number is.
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[Description]
Definitions
Teacher writes two definitions on the board:
A prime number is a number that has two different divisors only (1 and itself).
A composite number is a number that has more than two different divisors.
Students write the definitions in their notebooks.
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[File]
Sieve of Eratosthenes
Teacher gives the printed sheets to the students.
Then, teacher asks the students to cross out the numbers divisible by 2 (but keep the number 2).
Teacher asks the students to cross out the numbers divisible by 3 (but keep the number 3).
Teacher asks the students to cross out the numbers divisible by 5 (but keep the number 5).
And so on.
Teacher asks one student to read out the non-crossed numbers and tells the students that the remaining numbers are prime numbers.
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[Single activity]
Divisors
Teacher shows the problem and asks one student to solve the activity.
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[Single activity]
Prime numbers
Teacher shows the problem and asks one student to solve the activity.
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| 7. |
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[Description]
Summing up
Teacher sums up the lesson.
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