## Friday, December 16, 2011

### Divisibility Rules Overview

This is a quick overview of the divisibility rules.

1- Every number is divisible by 1.

2- If the last digit is an even number.

3- The sum of the digits is divisible by 3.

4- If the number is divisible by 2 at least twice.

5- If the number ends in 5 or 0.

6- If the number is divisible by 2 and 3.

7- (No rule.)

8- If the number is divisible by 2 three times
(I looked up "thrice" in an online dictionary and it's an actual word meaning three times. If you don't believe me, look it up yourself.)

9- If the sum of the digits is divisible by 9.

10- If the number ends in 0.

0- It is impossible to split a number into zero groups, even decimals can't be split into nothing.

Can you find out if a number like this: 2,617,628,132
is divisible by 4 and/or 8 mentally easily? If so create a divisibility rule for 7.
5x4+2-1x6+3-8÷4
20+2-1x6+3-8÷4
20+2-6+3-8÷4
20+2-6+3-2
22-6+3-2
16+3-2
19-2
17
I did the latest BEDMAS question.

## Thursday, December 15, 2011

### Practice Test question 2.

This is question 2 of the practice test.

### Common Factor

Common Factor- a number that 2 or more numbers are divisible by

eg. 4 is common factor of 8 and 12

### Common Factor

Common Factor- a number that 2 or more numbers are divisible by.

eg. 4 is a common factor of 8 and 12.

### G C F

G- Greatest C- Common F- Factor means the number with the greatest value that 2 or more numbers are divisible by.

### question 14

Faith and way made bamock for lunch . Faith cooked 5 8's of butter and Lucy cooked 1 8's of butter. Did they use all of it ? show your work.

answer no because 5 8's plus 1 8's equals 6 8's

### rule for 10

all numbers that end in 0(zero) are divisible by 10

### Multiples

Multiple - the product of any given number and natural number like 1, 2, 3...

eg. some multiples of 3 are: 3, 6, 9, 12, 15, 18...

Multiples:
2 - 2, 4, 6, 8, 10
3 - 3, 6, 9, 12, 15,
4 - 4, 8, 12, 16, 20
5 - 5, 10, 15, 20, 25

Multiples are just skip counting.

### Rule For 5

All numbers end in 0 or 5.
eg: 5,10,15,20,25,30,35,40 etc.

### Divisibility Rule For 10

All numbers ending in zero
eg: 10,20,30,40,50,60,70, ect.

### Chapter Review: #5

a) How do you know that 210 is divisible by 2, 5, and 10?
Answer - 2 goes into every even numbers, 5 ends with either a 0 or 5, 10 just ends with a 0.

b) How do you know 1232 is divisible by 4 and 8?
Answer - 4 goes into the number two times (2+2=4), 8 goes into it thrice (2+2+2=8).

c) How do you know that 333 is divisible by 3 and 9 but not by 6?
Answer - 3 goes into it after you add the numbers up and get the sum. Same rule for 9, 6 needs 2 and 3 for it to fit.

### Common Factors

The common factors is like this-

2- 4,6,(8),10,(12),14,(16),18,(20),22,(24),26,(28),30,(32),34,(36),38..etc

4-(8),(12),(16),(20),(24),(28),(32),(36),40..etc

There is this and there is a GTF which is..

Greatest common factor.

Common factor.

Least common factor.

..etc

### chapter review question 11

Subtract write each answer in lowest terms

a) 8/9-2/9=2/3
b) 9/14-1/14=4/7
c) 14/15-2/15=4/5
d) 23/24-11/24=1/2

### Divisibility Rule

All whole numbers are divisible by one

4 2 2
_ - _ = _
8 8 8

### divistblty rule

If the number is divisible by 2 and 3
It is divisible by 6

### divistblty rule

All numbers that are divisible by 2 twice are 4

### Divisibility rules

Rule for 5
Any number ending in 5 and 0

eg. 35,50,25,12345
All numbers ending in 5 or 0.

e.g: Odd numbers: 1,3,5,7,9

### Rule for 4

All numbers that are divisible by 2 twice.

### BEDMAS with brackets addition and subtraction

(91+12)-(3-1)+(2+12+5-3)
103-(3-1)+(2+12+5-3)
103-2+(2+2+5-3)
103-2+(4+5-3)
103-2+(9-3)
103-2+6
101+6
107

### Number of the day

Today`s Number of the day
1. 9643. 715
2. 482185.75
3. 9000+600+40+3+o.7+0.01+0.005
4.nine thousand six hundred forty three and seven hundred fifteen thousanths
4. 9700
5.7
6. 19287.43
8.14
9.1x1x1x1
10.3x3x3
11.6x6
12.27165400
13.9x6x4x3x7x1x5
14.3,7,5
20.9/7
21.1/3
22.61/5
_
23.0.3
24.000
25. 3%

A) 3 1
- + - =
4 4

B) 5 1
- + - =
8 8

C) 4 3
- + - =
10 10

### Rule for 2

All even numbers are divisible by 2

Eg. Even Numbers: 0,2,4,6,8

### Page 223 queston 17.

Jack is making vegetable dip for a party.
He needs 2/5 of a jar of mayonnaise to make it. The jar is 4/5 full. He drops it and only 1/5 is left.
a) Does he have enough left in the jar to make the dip? If not, how much more would he need?
b) How much of the jar spilled out?

a) He needs 2/5 so 1/5 is not enough. He would need 1/5 more.
b) 1/5 +3/5 would = 4/5 so he would have spilled 3/5

### Divisibility Rule For Five

All numbers ending in 5 or 0

eg. 5,10.15,20,25 etc.

Try 10= yes because it ends in 0
25= yes because it ends in 5
12= no because it ends in 2

### Today's BEDMAS question

Today's BEDMAS question was:
5x4+2-1x6+3-8÷4
20+2-1x6+3-8÷4
20+2-6+3-8÷4
20+2-6+3-2
22-6+3-2
16+3-2
19-2
17

### Divisibility Rule for 1

All whole numbers are divisible by one.

### Textbook: Chapter Review

1. TEWLSO EMRTS

When the numerator and denominator of a fraction have no common factors other than 1. (Two words)

### # of the day Question : 12

# 9643.715
12. Divided the number of the day with 3.55 and round
to the nearest hundredth

9643.715 divided by 3.55 =

2716.539400

That is the answer. You divide it then you go to the nearest hundredth and if the next number (tenths) is below "5" you make the hundredth number the same and change the numbers after it then you put them as "0". But if the tenth number is above the number "5" you make the hundredth number up by 1 number and you make the numbers after that "0".

9+15-6+18-4+4+13-12
24-6+18-4+4+13-12
18-6+18-4+4+13-12
11+18-4+4+13-12
29+18-4+4+13-12
47-4+4+13-12
42+4+13-12
46+13-12
59-12
71

## Wednesday, December 14, 2011

### Rule for 7

Take the last digit in a number.

Double and subtract the last digit in your number from the rest of the digits.

Repeat the process for larger numbers.

Example: 357 (Double the 7 to get 14. Subtract 14 from 35 to get 21 which is divisible by 7 and

we can now say that 357 is divisible by 7.

### Test

Study For Test On Thursday

### Multiples

The product of any given number and natural number like 1,2,3...
eg. Some multiples of 3 are: 3,6,9,12,15,18...
list the 1st 5 multiples of each number.
2-2,4,6,8,10
3- 3,6,9,12,15
4- 4,8,12,16,20
5-5,10,15,20,25
8-8,16,24,32,40
12- 12,24,36,48,60
Multiples are just like multiplying.

### How to do number 16 and 17 on Number of the day

Number 17- make a two digit number using the digit in ones place
first and the tens place second.
eg. 43 from December 7
Number: 9834.765
Then find from the prime factors
43-1, 43
so 43 is the only prime factor
1 is not prime.

Number 16- Only look at the whole number

Then go through the divisibility rules.

### Math Textbook pg.225

Number 12

I added the numerator, because, that's how you do it. When the fractions have like denominators, you only add the top.

### Denominator and Numarator

Denominator- the bottom number of a fraction
and tells us how many equal parts the whole is divided into.
eg.

Numerator- is the top number of a fraction and tells us how many parts
of the whole we have are dealing with.
eg.

### Subtracting Fraction with like Denominator

2/3-1/3=1/3

3/4-1/4=2/4 or 1/2

### divisiblty rules

If the number is divisible by 2 and 3
It is divisible by 6

### divisiblty rules

All even numbers are divisible by 2.

### divstiblty rules

All whole numbers are divisible by 1

### Test on Friday!

Just a reminder for the big test on friday!

### Practice Test (textbook pages 220-221)

4. a) 6/6 - 2/6 = 4/6 or 2/3
b) 2/3 - 1/3 = 1/3
c) 4/6 - 1/6 = 3/6 or 1/2

## Tuesday, December 13, 2011

### Common Denominator

A common multiple of the denominator of a set of fractions.Here is a link!