Y9 All Maths Formulae [End of years revision]

Percentage of an amount

Percentage of an amount

percent x amount

100

Density

mass

volume

Turn a fraction into a percentage

fraction x 100

Percentage change

change x 100

original

Area of a trapezium

a + b x height

2

Area of a parallelogram

base x height

Volume of a prism

cross sectional area x height (or length depending on your shape)

Weight (using mass)

mass x 10

Pressure

force

area

Capture-Recapture

Initially tagged = Recapture tagged

Population (x) sample size

Position of median

Number of items + 1

2

Lower quartile

(n + 1) th value

4

Upper quartile

3(n + 1) th value

4

Mean

total fx

total f

Circumference of a sector

angle x 2πr

360

Area of a sector

angle x πr²

360

Compound interest

starting money x multiplier^number of years

Area of a circle

πr²

Area of a triangle

base x height

2