4.1 Factors and Monomials 2.notebook
Warm­up 10/24/12
IAN p. 56
October 22, 2012
4­1 Factors and Monomials
IAN p. 57
Solve ­ Check each solution
Factors ­ of a whole number divide that number with no remainder.
1. x ­ 3 = 19
2. 2x = ­16
Example: Factors of 8
1, 2, 4, 8 are all factors each divide 8 with no remainder.
3. 5 + x > ­2
What are the factors of 24?
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Divisible ­ A number is divisible by another number if there is no remainder after dividing.
Divisibility Rules ­ Shortcuts to determine if a number is divisible by another number.
A number is divisible If…
by :
Example:
the number is even or ones digit is divisible by 2.
24 can be divided by 2
if sum of digits is divisible by 3. 165: 1 + 6 + 5 = 1212 is divisible by 3
last two digits of number is divisible by 4.
5,248: 48 is divisible by 4
Divisibility by 7
To determine if a number is divisible by 7, take the last digit off the number, double it and subtract the doubled number from the remaining number. If the result is evenly divisible by 7 (e.g. 14, 7, 0, ­7, etc.), then the number is divisible by seven. This may need to be repeated several times.
Example: Is 3101 evenly divisible by 7? 310 ­ take off the last digit of the number which was 1
­2 ­ double the removed digit and subtract it
308 ­ repeat the process by taking off the 8
­16 ­ and doubling it to get 16 which is subtracted
14 ­ the result is 14 which is a multiple of 7 ones digit is a 5 or 0. 560 or 465
number is divisible by both 2 and 3.
12: can be divided by 2 and 3
if last three digits of 4,824: 824 is divisible number is divisible by 8.
by 8.
if ones digit is a zero. 450
is sum is divisible by 9
9 + 9 + 9: 27 Is 146 divisible by the following?
Number
2
3
Divisible: Yes or No
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Reason
The 78 members of the Brookhaven High School Marching Band will be performing in the July 4th parade. They want to walk in rows of 6, but want every row to have 6 members. Can they be arranged in rows of 6?
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Hint ­ Test 78 for divisibility by 6.
4
5
6
10
1
4.1 Factors and Monomials 2.notebook
October 22, 2012
A friend sends you a text message signed with the IAN p. 56
code number 5,385. Dave's number is divisible by 3, 5, and 8. Janice's number is divisible by 2 and 3, but not 4.
Joshua's number is divisible by 4 and 5, but not 3.
Karen's number is divisible by 3 and 5, but not 8.
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Who sent the text message?
Monomials
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Monomials are:
integers ­ 4, 3, ­2, 1 variables ­ x , y, z, a
product of integers and variables­
4x, ­3y, 2ab
Monomials can not have any addition or subtraction.
Homework:
Workbook page 21
Are the following monomials?
• ­4b
• 4(5 + x)
• 3c ­ 4
Homework:
http://www.watchknow.org/Video.aspx?VideoID=4042
Due October 15th
Create your own Divisibility Rules Song, Rap, or Poem
Must include Divisibility tests for
2, 3, 4, 5, 6, 8, 9, 10
http://www.vectorkids.com/vkdivisible.htm
May work with one partner
Be prepared to share
2