Mathematics Prep for maths exam

Page 1

Calculating mean, median, and mode (+range)

Mean: Add up all the numbers in a data set together, then divide by how many numbers there are

Median: order the numbers of the data set from smallest to largest, then cross off numbers starting from the bottom then jump to the top, and then cross out the second smallest number, then jump to the second biggest, then third, then fourth, and go on until you reach the middle number. If there are two numbers in the middle calculate the mean of those two numbers, and that will be your answer

Mode: Order numbers from smallest to largest, then scan the data for the most recurring number

EX: 1,3,6,7,7,7,9,11,11 The mode is 7.

Range: range is not an average however, it is still useful to find out the range of a data set. To find the range you must do the biggest number minus the smallest number of a data set.

TRY IT YOURSELF:

find the mode median mean and range for the following data sets:

15,17,9,9,9,0,7,66,7

Mode: 9

Median: 9

Mean: 15.4

Range: 17

Page 2

Linear equations, how to solve them and how to graph

How to solve an algebraic equation:

EX: 9X+4=40

first you must get rid of any extra numbers on the side of X, and leave 9X by itself to do that you must subtract 4 from the positive 4 because 4-4=0 but whatever you do to one side you have to do to the other, so it would 40-4 which would be 36. Then all you have left is 9X, but we want only X not 9X so 9X basically means 9 multiplied by X, so we must divide 9 by X, but whatever you do to one side you must do to the other, so that would be 9 divided by 36 which = 4. So X=4

Let's make it more complicated shall we?

Now you have a variable on both sides of the equation

EX: 4X + 3 = 2X +15

so how do we solve it?

1) First, we subtract 3 from both sides so it becomes 4X=2X+12

2) then you must get rid of the extra Xs, which side has the least amount of Xs 2x!!!!

So we subtract 2X from both sides

so that gives 2X=12

so then we just divide 12 by 2 and VIOLA~ finito X=6!

To graph linear equations you must know the following equation Y=MX+C, C being the Y intercept, and M being the slope.

EX: the equation 3X-1 you intercept -1 on the Y axis. and as for the three, every time you go up one you go three to the right

Page 3

Geometry area + perimeter

area of a square/rectangle: b1 X b2

area of a triangle= b1 X b2 divided by 2

area of a trapezium = B1 + B2 X height divided by 2

Area of a circle = 3.14 X R 2

CIRCUMFERENCE of a circle: R X 3.14

PERIMETER: Just add all the sides together EXCLUDE THE HEIGHT

REMINDER: ALWAYS PUT 2 AT THE END OF A MEASUREMENT WHEN CALCULATING AREA DO NOT PUT ANYTHING (EXCEPT UNIT OF MEASUREMENT) AFTER CALCULATING PERIMETER. WHEN DOING VOLUME ADD 3 AT THE END OF A MEASUREMENT>

Page 4

Geometrey angles

Obtuse angle : going over 90*

Acute angle: under 90*

Right angle: exactly 90*

remember the opposite angle rule, the angle opposite to it will always have it be something that adds up to 180* when doing it on a straight line

Supplementary angles: adds up to 180*

Complementary angle: adds up to 90*

Page 5

Unit of measurments

there are 10 mm in one cm

there are 100mm in 1 decimeter

there are 25.4 mm I one inch

There are 1000 mm in one meter

There are 1,000,000 mm in one kilometer

There are 10 cm in one decimeter

There are 2.5 cm in one inch

There are 100 cm in one meter

There are 1000 cm in km

There are 40 inches in one meter

There are 3937 inches in one km

There are 1000 meters in one kilometer

There are 3ft in 1 yard

There are 1760 yards in one mile

There are 5280 feet in one mile

There are 16 ounces in 1 pound

There are 14 pounds in one stone

There are 224 ounces in one stone