Slides in this set
Types of Numbers
Square Numbers any number times by itself.
Examples: 4 (2x2),9 (3x3),16 (4x4),etc
Cube Numbers any numbers times by itself 3 times!
(Like volume of a cube!)
Examples: 8 (2x2x2), 27 (3x3x3), 64 (4x4x4),etc
Powers how many times a number multiplies itself by.
Example: powers of 2:
2² = 2x2 = 4
2³ = 2x2x2= 8
2 = 2x2x2x2= 16
Prime Numbers they only divide by themselves and
If the number ends in 1,3,7 or 9, it means that there is a
chance of it being a prime number but it doesn't mean
it is definitely a prime number! (e.g. 21,27 are NOT prime These are quite
numbers though they end in 1/7 as they both divide by basic you NEED
to know them!
Multiples, Factors and Prime Factors
Multiple = multiply = just keep multiplying!
Multiples the times table of that particular
number. E.g. the multiples of 3 = 3,6,9,12,15,18
........ So hard to explain =`=
....Please read it over
if you don't
Factors of a number are pairs of numbers that
you multiply to get another number.
e.g. factors of 24 = 1x24,2x12,3x8,4x6 (multiply
any of those pairs and you'll get 24!) just start
with 1 and keep going!
But- STOP when any numbers are repeated!
1x64 Factor of 64
5x 3,5,6,7 can't be divided into 64.
6x So leave it!
8x 8 Repeated
Don't write a number twice!
2x12 Factors of 24
4x6 Always start with `1' times the
Repeated numbers number!
`Factor trees' are used to find prime factors (prime
factors: a number broken down into a string of prime
numbers all multiplied together) Factor tree of 420 it
A factor tree looks like this: will show you the
prime factors of 420!
Each `level' of
`Level' 1 420 numbers multiplies to
get the number above
that level The numbers at the end
`Level' 2 42 42x10=420 10 (the ones in circles) are the
`Level' 3 6 5
Finally! The prime factors of 420 =2,3,7,2 and 5. You would get 420 by multiplying those
So it's usually written with times signs = 2x3x7x2x5
However examiners like to see numbers in the simplest form,
so we should write it like = 2²x3x7x5 (2²= 2x2)
LCM- Lowest Common Multiple The smallest number that
will divide by all of the numbers in the question.
Once you know how to do the prime factors LCM and HCF
LCM Example: Find the LCM of 42 and 36.
1) Find the prime factors of 42 and 36
2) 42=7x2x3 36=2x2x3x3
3) Circle the common prime factors
4) 42=7x2x3 36=2x2x3x3
5) Write down the ones you have circles ONCE =2x3
6) Then put the ones you haven't circled in the list=
This means if you wrote out all of the multiples
in both numbers, 252 will be the first number
that is common to both numbers. why…read more