Maths

• how do you figure out the longest side of a right angled triangle using pythagoras theorom?

  a2 + b2 = c2
• area of a triangle

  bxh / 2
• circumference of a circle

  πd or 2r2π
• what is the pythagora equation of a shorter side?

  a2-b2=c2
• SOHCAHTOA

  
• how do you figure out the gradient of a line

  rise/run
• how to figure out the median


  write them all out then cross the numbers until you get to the middle and have one number left.
• how to figure out the mode

  the most common number
• how to figure out the range

  taking away the biggest number from the smallest number
• equation of a line

  x1-y1/x2-y2
• Standard form

  A way to write really large or very small numbers, where numbers are recorded as a number between 1 and 10 multiplied by a power of ten. Also called standard index form or scientific notation.
• For numbers greater than or equal to 10, the power is a positive integer
• For numbers greater than or equal to 1 and less than 10, the power is zero
• For numbers less than 1, the power is a negative integer
• The power can be found by counting the number of places the first non-zero digit has moved to the right (for numbers greater than or equal to 10) or left (for numbers less than 1)
• Write a number in standard form

  1. Write the number as a value between 1 and 10

  2. Write x 10

  3. Write the power of ten
• how to figure out the total

  frequency x number of people
• Percentages are always written as decimals when calculating increases and decreases
• area of a parallelogram

  base x height
• percentage of a number

  1. find the percentage out as a decimal


  2. times it by the number
• how to figure out percentage increase

  1. Calculate the Difference Between the Ending and Beginning Value.
  2. Divide the Difference by the Beginning Value.
  3. Multiply by 100 to Convert the Decimal into Percentage Form
• area of a trapezium

  1/2(a+b) x h
• how to find an upper bound

  x0.5
• how to find a lower bound

  /0.5
• 1km


  1000m
• 1 hour

  3600s
• how to figure out the surface area of a cone

  πrl
• how to figure out the volume of cone


  1/3 π r2 h
• how to figure out the surface area of a cylinder

  2πr2 + πdh
• how to figure out the general function of a graph

  y=mx+c
• how to do addition with fractions

  1. Step 1: Find a common denominator.
  2. Step 2: Add the numerators (and keep the denominator)
  3. Step 3: Simplify the fraction.
• how to figure out the volume of a cylinder

  area of the circle x length
• how to figure out parts in a ratio

  1. add the ratio together


  2. then divide but the parts
• how to find a missing value

  1. divide the amount with the ratio e.g 52 /4 x 7
  2. 2. times by the amount of the part needed
• KFC

  key flip change
• how to figure out the HCF

  1. State the product of prime factors for each number, not in index form. (you can work these out using a prime factor tree)
  2. Write all the prime factors into the Venn diagram for each number.
  3. Multiply the prime factors in the intersection to find the HCF.
• how to expand brackets

  To expand a bracket means to multiply each term in the bracket by the expression outside the bracket. ≠For example, in the expression 3 ( m + 7 ) , multiply both and 7 by 3, so: 3 ( m + 7 ) = 3 × m + 3 × 7 = 3 m + 21 .
• rules of indices

  n*= 1
• speed = distance/time
• time = distance / speed