Prerequisite to chapter 5 Divisibility Rules To determine

Prerequisite to chapter 5 Divisibility Rules: To determine the rules of divisibility

Divisible When one number can be divided by another and the result is an exact whole number. Example: 15 is divisible by 3, because 15 ÷ 3 = 5 exactly But 9 is not divisible by 2 because 9 ÷ 2 is 4 with 1 left over.

Divisibility Rules n. A method that can be used to determine whether a number is evenly divisible by other numbers. n They are a shortcut for testing a number's factors without resorting to division calculations.

Here are the Divisibility Rules! A number is divisible by… n 2 if the ones digit is even ex. 542 1264 234, 567 236, 794 n 3 if the sum of the digits is divisible by 3 ex. 447 135 240 4, 408 n 4 if the number formed by the last two digits is divisible by 4 ex. 240 4, 408 234 624

Here are the Divisibility Rules! A number is divisible by… n 5 if the ones digit ends in a 5 or 0 ex. 45 3, 490 546 235 n 6 if the number is divisible by BOTH 2 and 3 ex. 7, 026 3498 8, 903 8, 440

Here are the Divisibility Rules! n 9 if the sum of the digits is divisible by 9 ex. 1, 287 8, 901 2, 984 50, 319 10 if the ones digit ends in 0 ex. 1, 450 570 3, 456 5, 490

Lets try a few! Is the first number divisible by the second number? 1. 447; 3 Yes 2. 419; 2 No 3. 7, 026; 6 Yes

A few more… 1, 287; 9 yes 5. 1, 260; 10 yes 6. 4, 480; 4 yes 7. 8, 930 no 4.

Determine whether each number is divisible by 2, 3, 4, 5, 6, 9, or 10. 712 2, 4 462 2, 3, 6 50, 319 3, 9 8, 340 2, 3, 4, 5, 6, 10

You try these! 8, 901 3, 9 1, 005 3, 5 920 2, 4, 5, 10 3, 498 2, 3, 6

On your own Page 554 Numbers 1 -23 odd

Chapter 5 FRACTIONS, DECIMALS AND PERCENTS

Lesson 1 Prime Factorization Objective: find the prime factorization of a composite number

Refresh your memories! Factor: Number to a multiplication problem 3 x 6 = 18 2 x 4 x 3 = 24 Product: the answer to a multiplication problem

Prime Number Whole number greater than 1 that has exactly two factors: 1 and itself. 2 (1 x 2) 3 (1 x 3) 5 (1 x 5)

Composite Number Whole number greater than 1 that has more than 2 factors. 4 (1 x 4 2 x 2) 6 (1 x 6 2 x 3) 12 (1 x 12 2 x 6 3 x 4)

Determine whether each number is prime or composite. 17 Prime (1 x 17) 12 Composite (1 x 12 2 x 6 3 x 4) 11 Prime (1 x 11)

Determine whether each number is prime or composite. (1 x 24 15 Composite (1 x 15 3 x 15) 24 Composite 2 x 12 3 x 8 4 x 6)

Every composite number can be written as a product of prime numbers in exactly one way.

Prime Factorization Expressing a composite number as a product of prime numbers.

Factor tree A diagram showing the prime factorization of a number. The factors branch out from the previous factors until all of the factors are prime numbers.

Here is a model! 96 6 2 3 16 2 8 2 4 22 96 12 8 3 4 4 2 22 22 5 2 x 3

Lets try more 18 28

You try these! 16 30

Here are two more! 22 43

Do Now Find the prime factorization of… 46 And 108

Factor each expression 10 ac 2 16 x

You try these expressions! 2 52 gh 2 2 48 a b

You try some on your own! Page 199 numbers 13 -35 odd Homework n Page 199 numbers 12 -34 even n Page 554 numbers 2 -24 even n You have a quiz on these 2 lessons Wednesday!