Math 6A, Lesson 1, Fall 2017, 9/10/2017
1. Factors: the number 12 can be expressed as the product of two smaller whole numbers as follow:
12 = 1 x 12
12 = 2 x 6
12 = 3 x 4
1, 2, 3, 4, 6, and 12 are called factors of 12. We say that 12 is divisible by each of its factors.
2. Multiplies: when a number is multiplied by a non-zero whole number, we get multiple of the number:
The multiple of 3 are: 3×1, 3×2, 3×3, 3×4, 3×5, …
That is: 3, 6, 9, 12, 15, …
The multiple of 4 are: 4×1, 4×2, 4×3, 4×4, 4×5, …
That is: 4, 8, 12, 16, 20, …
3. Link between factors and multiplies:
recall 3 and 4 are factors of 12. Interestingly, 12 is a multiple of both 3 and 4. The number 12 is a multiple of each of its factors 1, 2, 3, 4, 6, and 12.
4. Prime number, composite number, prime factor
- Prime number: a prime number is a whole number greater than 1 that has only two factors. 1 and itself. 2, 3, 5, 7, 11, 13, 17, 19, …
- Composite number: a composite number is a whole number greater than 1 that has more than two factors.
- Prime factor: a prime number that is a factor of a composite number is called a prime factor of the composite number.
5. Prime factorization methods:
- Factor tree: teaching on whiteboard in the class
- Continuous division: teaching on whiteboard in the class
- divisibility: https://www.khanacademy.org/math/pre-algebra/pre-algebra-factors-multiples/pre-algebra-divisibility-tests/v/divisibility-tests-for-2-3-4-5-6-9-10
6. Exponential notation:
Squared, cubed, fourth power, … teaching on whiteboard in the class
7. Home Work:
- Handout: two pages
- Workbook page 1: 1, 2, 3, 4, 5
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