Numbers BY SANDHAYA MATHS REVISION FACTORS, MULTIPLES, COMPOSITE and PRIME NUMBERS Factors are numbers that have a certain number as a multiple. For example the factors of 10 are 1,2,5,10. All numbers will have 1 and itself if they have more than two factors then it is called a composite number. If it is only 1 and its self it is a prime number.Multiples are numbers that can be made by multiplying the number by other numbers they never stop. You usually only have to go to 12 for ex. the multiples of 2 are 2,4,6,8,10,12,14,16,18,20,22,24. Lets test your knowledge now.

12.What are the factors of 39?

13.Is 49 a composite number?

14.What are the multiples of 5 up till 12?

15.Is 29 a prime number Answers

1,3,13,39

Yes

5,10,15,20,25,30,35,

40,45,50,55,60

Yes NEGATIVE NUMBERS Negative numbers are that are less than zero. If you subtract a big number from a small number you get a negative number. So for example 2 - 7= -5. When you add 3 + -5 = -2. When you add a positive number like 3 to a -5 number you go 3 numbers forward so get -2. When you subtract -3 - -5 you add 3=5 which equals 8 so you get -8. Question time.

16. 3 + -6 = ?

17. -4 + -4 = ?

18. 8 - 2 = ? Answers 5. 3 + -6 = -3

6. -4 + 4 = 0

7. 8 - 2 = -6 MIXED OPERATIONS A mixed operation is when you have different types of problems in one they look something like this 3 + 4 x ( 9 - 5 ) = 19. In a normal problem with only one type of equation you go right to left but in this problem you have to go by a certain rule. And that rule is PEMDAS. Parenthesis is the first thing, you do the question inside of them. Next comes exponents they are a number with a smaller number on top, lets say the big number on the bottom is 2 and the top number is 4 to solve it you do 2 x 2 x 2 x 2 = 16. Multiplication and division come next you don't do them in order but from left to right the same goes for addition and subtraction. Now do you get the idea? 8. 10 x 6 - ( 6 x 4 ) +17 = ?

9. 10 + 4 x 6 - ( 43 - 28 ) = ? Answers 8. 10 x 6 - (6 x 4) + 17 = 53

9. 10 + 4 x 6 - ( 43 - 28 ) = 19 DIVIDING AND MULTYPLYING BY 10 Dividing an multyplying by 10 is pretty easy when you multyply by 10 you add a 0. so 976896 times 10 is 9768960. if you have a decimal point like 23.9 you move the decimal point one place to the right so the answer will be 239. When you divide by 10 if there is a 0 at the end you take it away for ex. 60 ÷ 10 is 6. But if there is no 0 you add a decimal point ex. 56 ÷ 10 is 5.6 . Now lets say you Question Time!

1.8702 ÷ 10 = ?

2.7609 x 10 = ? 1. 8702 ÷ 10 = 870.2 2. 7609 x 10 = 76090 Data Mode, Median and Mean Mode, median and mean all relate to graphs and data. How do you find the mode? Easy, the mode is the number that appears the most often. So the mode for 2,3,4,5,6,6,7,8 is 6. The median is the number in the middle set in order, but if there are two numbers in the middle for example: 2,3,3,4,5,6 you 3+4÷ 2 = 3.5. The mean is the average of the set of numbers. To find the mean you add up all the numbers and divide them by the numbers divided.So the mean of 3,4,5,6,6,7,8 is 3+4+5+6+6+7+8 = 39 ÷ 7 = 5.4 Questions

32.What is the mode of 2,2,3,3,4,5,5,5?

33.What is the median of 1,,2,3,4,5,5,6,?

34.What is the mean of 2,3,4,4,5,5,6? Answers

32. 5

33.4

34.4.1 Geometry Polygons A polygon is a shape with straight lines and is closed. There are two types of polygons irregular polygons and regular polygons. An irregular polygon is a shape with no sides and angles equal. A regular polygon is a shape with all angles and sides the same. A square is a regular polygon cause all sides are equal and the angles are equal too. Question 25.What makes these shapes a regular polygon?

26. Is a rectangle a regular polygon? 25. They all have same sides and angels.

26. No Answers Area of A Triangle To find the area of the triangle you multiply the base times height of the triangle which gives the area of a quadrilateral so that's why you have divide it by 2. If all three sides are different then you have to draw a line from the opposite angle to the base which creates a right angle. Then measure it and call that the height. Then do multiply base times height divide by two. Questions

27. What is the area of this triangle?

28. What is the are of this triangle? Answers

27.20

28.14 Percentages A percentage is just like a fraction its a part of a whole. 1/2 equals 50% so the whole is 100% To find a the percentage of something you tearn it into a fraction. For example 20% of 120 to f ind that out you have to do 20/100 x 120 = 5/120 which is a whole number so 20% of 120 is 24. Question

7.What is 40 percent of 160. Answer

7.40 Number System There are many different number systems, I'm going to talk about four of them Babylonian, Roman, Egyptian and Hindu-Arabic.

In the Babylonian system there are 3 symbols . So as you can see there is 60, 10 and 1. There is also an example on how to write it. For the Romans they decided to make a more confusing style.

The Roman Way

1=I 2=II 3=III 5 =V 10=X 50=L 40=XL 100=C 500=D 100 = M. So the number 2764= MMDCCLXIV The Egyptians also have a confusing way to write numbers.

So the number 2 316 has 2 pics of 1000 and 3 pics of 100 and i pic of 10 and 6 pics of 1. Equivalence Equivalence means something is the same but can be in a different form. For example 0.25 = 1/4 or 2/4 = 1/2 or 2/3 + 1/3 = 6/9 + 3/9. Hindu-Arabic numbers is the numbers we do use now days. Question Question

What does 1/2 equal too in a decimal, percentage

and in a centimeter? Answer

0.5 50% and 5mm Money Exchange Rates AUD $1 =

$0.90 CAN

$1.29 SGD

$7.09 HK

28.10 THAI BHAT Examples

So if I bought a pen that is $4 AUD how much Canadian dollars would it be.

To find that out I would do 4 x 0.90 = 3.60. So the answer would be $3.60. Questions

23.How much would 3 calculators which are $3.50AUD into Canadian dollars? Answer

23.$9.45. Balance Sheets Date Transaction Debit Credit Balance 2012 $650.00 2 Feb 2012 ATM $30.50 $619.50 3 Feb 2012 Salary $600.50 1220 4 Feb 2012 Guess $450.67 a. Question

24.What is the answer for a.? Answer

24.$769.33 Operations With Money Withdrawal: When you take money out of your account.

Deposit: When you put money in your account.

Transaction: A withdrawal or deposit.

Salary: The money your job pays you.

Debit: Money from your account.

Credit: The money put in your account.

Balance: The balance of money in your account.

Cheque: A written agreement to payment.

ATM: Automatic Tela Machine

Eftops: Like a debit card.

Intrest: How much charge you pay extra. Decimals Decimals are parts of a whole too. You use decimals if there are ten, hundreds and thousands ect parts of a whole. You can turn a fraction into a decimal by making the denominator into a ten, hundreds or thousands. 1/4 = 0.25. Questions

How much is

3.3/4,

4.5/10,

5.2/5,

6.3/25 in decimals? Answers.

0.75,0.5,0.4,0.12 Mass 100mg=1g

100g=1kg

1000=1tonne (t) 2756kg = 2.756 t Questions

29.36475kg = ?t

30.3452kg= ?g Answers

29.3.647t

30.34520g Symmetry Rotational symmetry: A shape has rotational symmetry when it can be turned once on its central point and fits upon itself at least once before making one full turn.

Line of Symmetry: A line of symmetry is when one shape can be folded along its axis and be exact with the same side. A star has rotational

symmetry so does a square. Questions

31.Does a equilateral triangle have rational symmetry? Answer

32.Yes Graphs Bar Graphs show data from a frequency table.

A pie chart is a circular graph that represents shows different amounts in a fraction

A line graph shows a plot of data over time Questions

35. What graph would be good to find out what is the most common pet? Answer

Bar Graph

Pie Graph Operations With Fractions To add fractions like 1/4 + 1/4 you add the numerators so the answer is 2/4. But to add 1/2 + 3/4 you find the LCM for 2 and 4 which is 4. So to change 2 to 4 you times 2 whatever you do to the bottom you do the top. So it would be 2/4 + 3/4 = 1 and 1/4. 10.What fraction is the top?

11.What is 3/5 + 4/19 =? Answers

10.3/4

11.77/95 Patterns Rule 1 2 3 4 x 2 +3 5 7 9 * + 3 4 7 19 x 3 +2 5 8 * = squared Fill in the blanks Answers

11

12

11

14 Time Zones +15ºE = +1hour

+15ºW= -1hour Question

36.If it is 45ºE what time is it? 36.Answer 3am Remainders as Decimals Lets say you do 27/4 the answer 6R7 you add a decimal point and keep dividing. You end up with 6.75 Question

19.32/5 Answer 6.4 Large Numbers Work out large numbers by multiplying small sections by the number of sections in the whole. 22.A person who lives for 2 years has lived for how many minutes? 22.Answer 31557600 Thank You For Watching

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