Section 1 - Number Flashcards
What’s an integer
It’s another name for a whole number - either s positive or negative number or 0
What are rational numbers
They can be written in 3 forms
Integers
Fractions
Terminating or recurring decimals
What are irrational
They can’t be written as fractions - they are never ending, non repeating decimals. Square roots of positive integers are either integers or irrational eg square root of 3 is irrational but square root of 4 is 2 and so is rational
Pi is irrational
What does bodmas stand for
Brackets Other Division Multiplication Addition Subtraction
Tells you the order which operations should be done
What’s the reciprocal
The reciprocal of a number is just 1 divided by the number eg 1/8
What are the multiples of a number
Just it’s time table we some multiples of 8 are 16,32
What are factors
Factors of a number are all the numbers that divide into it
Eg factors of 12 are 1, 12, 6, 3, 4
What’s a prime number
A number that’s only factors are itself and 1 - only exception is one which is not a prime number
How do you find the prime factors of a number
Can be broken down into a string of prime factors all multiplied together - called prime factor decomposition or prime factorisation
How do you make a prime factor tree
Start with the number at the top and split the number into factors
Every time you get a prime number ring it
Just keep factorising the numbers, then write out the primers in numerical order and if there’s more than one the same - put it as a power
Eg prime numbers are 2 X 2 X 3 X 5
Do 2^2 X 3 X 5
What’s the LCM
Least common multiple
The smallest number that will divide by all the numbers in the question
so LCM of 12 and 15 is 60
Lowest common MULTIPLE
What’s the HCF
The biggest number that will divide into all the numbers in the question
Eg the HCF of 36 and 54 is 18
How do you cancel down
To cancel down or simplify a fraction, divide top and bottom by the same number until you can’t
What’s a mixed number
With an integer and a fraction part .
What’s an improper fraction
Where the top number is larger than the bottom number - need to be able to convert mixed numbers to improper fractions and other way around