M4

Question 1

Pythagoras

Answer 1

a2=b2+c2

Question 2

Median

Answer 2

(n (how many numbers) + 1 /2) th position

Question 3

Mean

Answer 3

EFX/EF

Question 4

IQR

Answer 4

UQ-LQ

Question 5

LQ

Answer 5

25% of the data

Question 6

UQ

Answer 6

75% of median (LQx3)

Question 7

Boundaries when + or x

Answer 7

max = a max +x b max
min = a min +x b min

Question 8

Boundaries when - or /

Answer 8

max = a max -/ b min
min. a min -/ b max

Question 9

Finding a % of a quantity

Answer 9

Percentage changed to fraction x quantity

Question 10

Percentage increase

Answer 10

Change percentage to a decimal then add to 1.00 and x by original

Question 11

Percentage decrease

Answer 11

Change percentage to a decimal then take away from 1.00 and x by original

Question 12

A quantity as a percentage of another

Answer 12

Write as fraction then x 100

Question 13

Percentage change

Answer 13

Actual change / original x 100

Question 14

Original quantity

Answer 14

Find 1% then x100 to get 100%

Question 15

Simple interest

Answer 15

Change percentage interest to a decimal then add to 1.00 then x by money invested. Take original away to find interest money. X this by the number of years invested

Question 16

Compound interest

Answer 16

original amount x interest (added to 1.00) to the power of years

Question 17

Midpoint

Answer 17

(x1 x x2 / 2, y1 x y2 / 2)

Question 18

Gradient

Answer 18

Rise / run (downhill lines have negative rise values - ‘fall’)

Question 19

Length of a line

Answer 19

Find 2 sides using rise and run, then Pythagoras the hypotenuse

Question 20

Straight line graphs

Answer 20

y = mx + c

m = gradient
c = y- intercept

Question 21

Perimeter

Answer 21

All sides added together

Question 22

A of square

Answer 22

side length squared

Question 23

A of rectangle

Answer 23

L x B

Question 24

A of triangle

Answer 24

b x h / 2

Question 25

A of rhombus

Answer 25

diagonal 1 x diagonal 2 / 2

Question 26

A of kite

Answer 26

diagonal 1 x diagonal 2 / 2

Question 27

Force

Answer 27

Pressure x Area

Question 28

Pressure

Answer 28

Force / Area

Question 29

Area (force triangle)

Answer 29

Force / Pressure

Question 30

A of circle

Answer 30

πr squared

Question 31

Circumference of circle

Answer 31

2 πr or πd

Question 32

A of sector

Answer 32

θ/360 x πr2

Question 33

A of arc

Answer 33

θ/360 x 2 πr

Question 34

Frequency (histograms)

Answer 34

Frequency density x class width

Question 35

frequency density

Answer 35

Frequency / class width

Question 36

V of cube

Answer 36

length of side squared

Question 37

SA of cube

Answer 37

6 x area of one face

Question 38

V of cuboid

Answer 38

L x W x H

Question 39

Surface area

Answer 39

Area of all faces added together

Question 40

V of cylinder

Answer 40

πr2h

Question 41

CSA of cylinder

Answer 41

2 πrh

Question 42

Total SA of cylinder

Answer 42

2 πrh + 2 πr2

Question 43

CSA of frustum

Answer 43

πrL (big) - πrL (small)

Question 44

Total SA of frustum

Answer 44

CSA + πr2 (small) + πr2 (big)

Question 45

V of frustum

Answer 45

Vbig - Vsmall

Question 46

What does small mean in frustum equations

Answer 46

Small cylinder - the piece that has been cut off

Question 47

What does big mean in frustum equations

Answer 47

Big cylinder - the total of the frustum and cut off, smaller cylinder

Question 48

Mass

Answer 48

Density x Volume

Question 49

Density

Answer 49

Mass / Volume

Question 50

Volume (mass triangle)

Answer 50

Mass / Density