TT6 week 11 lessons 43-45

A factor of a number is a number that divides the given number evenly or exactly, leaving no remainder.
Eg. 2 and 3 are factors of 6.

1. know your multiplication tables

2. know your divisibility rules

What numbers can you multiply together to equal 20? What are the factors of 20?

The Greatest Common Factor is the largest factor that any two numbers have in common. This is useful to know when reducing fractions or simplifying equations. Knowing the GCF will help you create equivalent fractions as well. We will get to that later.

Make a list of all the factors for each number and find the largest one they both have.

Factor both numbers down to prime numbers. If they share 2 prime number factors, multiply those numbers to get the GCF.

If they share only 1 number, that number is the GCF.
If they share no numbers, 1 is the GCF.

We can use the GCF to reduce fractions. Just as we found equivalent fractions by multiplying or dividing the numerator and denominator by the same number, we can fully reduce a fraction all the way down to its simplest form by using the GCF.

Prime numbers are numbers that are only divisible by 1 and themselves. Eg, 3 is only divisible by 1 or 3, therefore it is prime.

There are a lot of prime numbers. We use them when we factor numbers to find

​Memorizing prime numbers can save you time in math. Or you could just add the chart to your notes. ;)

​We use prime factorization in math to simplify expressions or equations quickly.

A composite number is a positive integer greater than 1 that has more than two factors. Unlike prime numbers, which are only divisible by 1 and themselves, composite numbers can be divided evenly by other numbers. The smallest composite number is 4, and examples include 6 (divisible by 1, 2, 3, and 6) and 9 (divisible by 1, 3, and 9).  

Homework: Chapter 8 lessons 43-45.

Math lab today 2:30-3:30 in Google.