Transcript LCM & HCFtues L1

L/O:
To recognise and
use multiples, factors, LCM
and HCF
10 April, 2016
Multiples and Factors
Use your tech savvy skills and find and write the
definitions of in your work book:
Proper fractions, Improper fractions, Mixed numerals,
HCF- Highest Common Factor
LCM- Lowest Common Multiple
Work in pairs and come up with
an example to show :
1. How do we change an improper fraction
to a proper fraction.
2. Change a Proper to an improper fraction.
Multiples
A multiple of a number is found by
multiplying the number by any whole number.
What are the first six multiples of 4?
To find the first six multiples of 4 multiply 4 by 1, 2, 3,
4, 5 and 6 in turn to get:
4, 8, 12, 16, 20 and
24.
Lowest Common Multiple (LCM)
The lowest common multiple (LCM) of two
numbers is the smallest number that is a multiple
of both the numbers.
Multiples of 6
12
6
8
18
16
Multiples of 8
54
24
30
32
40
36
48
42
56
60
64
66
102…
72
78
80
88
84
96 104 …
90
What is the lowest common multiple (LCM) of 8 and 10?
8
10
16
20
24
30
32
40
48
56
64
40
50
60
70
80
72
90
80
…
100
…
The lowest common multiple (LCM) of 8 and 10 is 40.
What is the LCM of 5 and 8?
Starter: FIND the LCM of the FOLLOWING:
a)2 & 8 b)6 & 9
e) 5 & 7
c)4 & 6
d) 4 & 3
f) 8 & 10 g) 8 & 7
h) 3 & 8
L/O:
To recognise and
use multiples, factors, LCM
and HCF
10 April, 2016
Multiples and Factors
STARTER
Copy and complete the following:
–3 × 8 =–24
–36 ÷ 9
42 ÷ –7
54
= –6
= –4
÷ –9 = –6
–12 × –8 = 96
–7 × –25 = 175
47 × 3
–4 × –5 × –8 –160
=
= 141
–72 ÷ –6 = 12
3 × –60 -12
÷
= 15
LCM and & HCF
• L/O: To recognise
and use multiples,
factors, LCM and
HCF
• Must know your times
tables
• Could calculate the
factor of an integer
• Should calculate the
HCF of two numbers
Factors
A factor is a
number that divides exactly into another
number.
Factors come in pairs.
For example, what are the factors of 30?
1
2
3
5
and 30
and 15
and 10
and 6
So, in order, the factors of 30 are:
1, 2, 3, 5, 6, 10,15 and 30.
The highest common factor (HCF)
The highest common factor (or HCF) of two numbers
is the highest number that is a factor of both
numbers.
HCF of 36 and 45
Factors of 36
are :
1,
2
,
3
,
4
,
6
,
Factors of 45
are :
1,
3
,
5
,
9
,
15,
The HCF of 36 and 45 is
9
.
9
,
45
.
12,
18,
36
.