Maths Flashcards
Probability is
1 minus the probability the event will happen.
1 - 0.5 = 50% chance
1 - 0.25 = 25% chance
1 - 0.25 = 25% chance
Must all equal back on one
What must you not forget when doing long multiplication on double/treble digits.
Bring down your zeros!!!
How do you get the answer for long multiplication for double digit+ sums
Do each line
Bring down your zeros
Add each line together
What is the number your dividing called?
The dividend
What is the number you dividing BY called?
The divisor
What’s answer called in long division?
The quotient
What’s the name of the formula symbol for long division?
The bus shelter
How to you add decimals to long division sums?
Add zero’s
Bring them down
Dave (bottom left) =
Density
Maggie (On top) =
Mass
Victor (bottom right) =
Volume
How do you get Density?
Maggie lies on victor (Mass divided by Volume)
How to do you get volume?
Maggie lies on Dave (Mass divided by Density)
Maggies a dirty bitch!
How do you get Mass?
Dave screws (x) Victor
Scaife (Bottom right) =
Speed
Tristan (Bottom left) =
Time
David (Top) =
Distance
Degree’s of a Triangle
180c (Half a square)
3 x 60c in equal triangle
Degree’s of square
360c
4 x 90c
Degree’s of pentagon
540c
1 Square + 1 Triangle
Range
The DIFFERENCE between largest and smallest number
Mode
The number that appears the MOST
Mean
The total of numbers divided by how many there are
Median
The number that is in the middle, or is the middle value.
How do you convert hours to minutes
Divide number by 60
14mph x 25 minutes
25/60 = 41.66
41.66 x 14 = 5.83
Nasty cyclist quesiton
How do you get speed?
David over Tristan
How do you get distance?
Scaife X Tristan
How to you get time?
David over Scaife
How to calculate surface area - 2 Dimensions
Length (Longest side) x width
How to calculate surface area - 3 Dimensions
Length (Longest side) x
Width (Medium side) x
Height (Shortest side)
How to calculate surface area - Box
Length x wide x depth
How to find surface area of an equally sized cube
Calculate one side and times x 6
EG
4 cm L x 4cm = 16cm squared
x 6 = 96cm squared
How to find surface area of triangle
Base x Height
Divide by 2
PI up to 5 Decimals
3.14159
How to find area of a circa
Radius (half the diameter)
Square the radius
Multiply by PI (3.14)
= Answer in CM squared
What does ‘Estimate mean’
Use an approximate answer
Usually a round number
How to do you check an answer
Reverse it
Divide for multiplication (Vice versa)
Add for subtract (Vice versa)
What do you do when you see a number next to a letter - EG
2.67a
Multiply!
a = 8
2.67 x 8
How do you get the most accurate miles/speed questions
Use all decimals
How do you build up positive marks?
Show all your workings - Look out for large mark questions
How to work frequency tables
- Find the mid-point (Total divided by 2)
- Times Frequency by mid-point
What happens next depends on the question
How do you calculate original prices from percentage drops?
In the scenario the price has dropped 18% (82% of the original)
82 / The price
x 100 = Original price
82 / 22,000 = £268.29
x 100 = £26,829.37 (Original price)
Check by minus off the original parentage
How do you convert a mixed number to a fraction
Multiply the whole number by the bottom of the fraction
Add the result to the top of the fraction.
This may then display as an improper fraction (where the top is bigger than the bottom)
How to convert a fraction to a mixed number
Divide top number by bottom number (To get remainder)
The whole = Result of division
Remainder = Top of fraction
Bottom = stays the same
BIDMAS?
The order that calculations should be done
Order of BIDMAS?
Brackets
Indices (Little numbers after letters)
Division
Multiplication
Addition
Subtraction
How to change decimal into fraction?
Multiply Decimal by 100
Write the result as the top number
The bottom number is 100
Use equivalent fractions
How to change fractions into decimals - Simple
Divide top by the bottom
How to change fractions into decimals - Harder fractions
Multiply top number by 10
Divide by the bottom number
Divide result by 10
What does ‘Of’ mean?
Multiply
How to add and subtract decimal numbers
Line the numbers up over one another
Ensure whole numbers and decimal numbers line up
Add zero’s for any gaps
Use normal manual adding and subtracting methods
How to multiply decimals
Ignore the decimal points 12.2 x 12.2
Multiply the two numbers as wholes 122 x 122
Add up the decimal points 1 + 1 = 2
Adjust answer by number of decimals
148.84
How to divide a decimal by a whole number
Set up the division sum as you would normally
Write a decimal point on the top line in the same place
Work left to right as normal
Dividing decimals (you will need fractions)
4.18 / 0.03
Write the division as a fraction (45.18 over 0.03)
Multiply the both 100 (4518 over 3)
Complete the whole number division
Thats it.
How to calculate percentage change
Divide new value by original
Convert to percentage 0.25 x 100
Subtract 100% to find the change
How to find out parameter?
Add up all sides
How to find circumference of circle
Diameter x PI
Make sure you have diameter and not radius (half diameter)
How to you convert metres squared to metres cubed
Divide by 10
How to find the surface area of 3d objects
Multiply height by length of each face
Add them all together
How to you find the volume of something
Multiply everything
Circles x PI
Area
Circumference
Radius squared
Diameter
How to calculate volume of a prism
Area of base: multiply and divide by 2
Multiply by length
How to work out ratio’s
Add the ratio up (1:5) = 6
Divide the ratio by total = 72/6 = 12
