M7 Flashcards
How many kilometres is 1 mile
1.6 kilometres
How to convert km into miles
number of km divided by 1.6
how many pounds is 1 kilogram
2.2 pounds
What is 1 litre in pints
1.75
What is 1 gallon in litres
4.5
What is a ratio
1:4
For every 1 part of something we need 4 parts of anotherH
How do you do a ratio in different units
- Convert larger unit to smaller units
2 simplify ratio as normal
if the exchange rate is £1 to $1.70 how much does it cost to convert my £56 into dollars (
56 x 1.7 = £95.20
if the exchange rate is £1 to $1.70 how much is $12 in pounds
12 divided by 1.7 = £7.06
How do you do sharing in a given ratio
- add up the ratio into total number of parts
- divide total amount by number of parts
- the number is what each part is worth
- Multiply by ratio to find each persons share
what are the rules of indicies
- Multiply powers of the same number add the indices
- divided powers of the same number subtract indicies
- to find the power of a power multiply indices
- anything to the power of 0 is equal to 1
- Negative indicies means the reciprocal
Standard form rules (using a x 10*)
A must be between 1 and 10
* must be a postive or negative WHOLE number
(When the number is large * is postive)
(When number is small * is negative)
How to add and subtract in standard form
Convert numbers from standard form into decimal form or ordinary numbers
complete calculation
convert back to standard form
How to multiply and divide using standard form
multiply or divide the first numbers
apply the index laws to powers of 10
ensure final answer is in standard form
How is dot notation used
one dot above number that number repeats
two dots above two numbers they repeat in that order
two dots in begining of number sequence at and at end they show begining and end of recuring group of numbers
What are surds
Surds is an expression that includes a root symbol. e.g. √2
what is answers in surd form
when you end the question with √ instead of square rooting it
Area of a circle formula
A = π r²
circumfrence of a circle
2πr or πd
in a non calculator paper what do you do with area and perimeter
leave pie in the answer
What is the surface area of a cone
πrl+πr²
In re-arraging formula if the letter appears more than once what do you have to do
factorise
What is the equation of a straight line
y = mx +c
m =gradient
c = y intercept
how to solve simultaneous equations through a graph
do x y table then plot graph and point of intersection is what each letter means e.g. (-1,-2)
x = -1 and y = -2
(if equation isn’t inform y = mx + c use zero-zero method)
how to do simulataneous equations by substitution
You ut one variable from one equation into the other. final equation will only have one unknown variable. then you must go back and work out other variable
e.g
Equation 1: y = 6 - x
equation 2: 2x + y = 8
Substituted: 2x+ (6 -x) = 8
Simultaneous equations by elimination
- scale up each term in one or both equations to make coefficients the same for either x terms or y terms
- Solve the equation after eithing subtracting the terms if the sign in front are the same or adding if the signs in front are different
- go back and solve the other term
Rules for simultaneous equations by elimination
Subtract if signs in front of terms are the same
Add if the signs in front of terms are different
what is trial and improvement
you make a table where you change what amount x is until you make for example 3x = 20. must comment if it too small or too big
(some say i’m too big)
Formula for probability
number of ways of achieving success divided by the total number of possible outcomes
How do you know if triangles are similar
Two triangles are similar if the angles are the same or the coresspnding sides are in the same ratio. either conditions met triangle similar
What is the formula for probability of something not happening>
1 - probability it does happen
What is the formula for expected frequency
(probability of success) x (number of trials)
What is the formula for relative frequency
Number of successes divided by sample size
Addition rule (OR)
P(A or B) = P(A) + P(B)
Multiplication Rule (and)
P(A and B) = P(A) x P(B)
