Transcript multiplication and more

Multiplication and
other Math Concepts
Math
The more you use math, the more you
realize how all the parts of math are
connected to each other like pieces of a
puzzle.
Fifth Grade Math Topics
Number Operations
Addition/Subtraction
Multiplication/Division
Decimals
Understanding
Operations Using Decimals
Fractions
Understanding
Operations Using Fractions
Percent
Understanding
Operations Using Percent
Exploring
Multiplication
Multiplication is used in just about
every aspect of math!
Multiples/Factors
Multiples are made by taking a particular number and multiplying it a certain amount of
times.
Factors are numbers that you use to multiply and make a product (answer)
The first 2 columns are multiples of 6 and 60. The last list of numbers are factor pairs of
480.
6
12
18
24
30
36
42
48
54
60
66
60
120
180
240
300
360
420
480
540
600
660
1,480
2,240
3,160
4,120
6, 80
8, 60
10, 48
12, 40
16, 30
20, 24
Rounding
When multiplying
numbers it might help to
round them first and get
a ballpark figure of what
the product is.
Click on this link to
practice some
multiplication now:
http://kidshub.org/kids/mult
iplication.cfm
Multiplying/Rounding
For example when
multiplying 52 x 19, you
could round 19 to 20.
Then multiply 20 by 50 and
20 by 2.
Finally subtract 52
(You only wanted 19 groups of
52, not 20)
20 x 50 =1000
20 x 2 =
40
1040 – 52 = 988
When multiplying large
numbers it may help to
round numbers and use
Look for Patterns
When trying to list
factors of a
particular number try
patterns like
doubling and
halving.
1 x 300 = 300
Double 1 and Half 300 to find
another pair of factors
The result is 2 x 150 and you
arrive at the same product
(300).
Divisibility Rules
Numbers follow certain rules which tell us something
about their factors.
For example if you take the digits of a number and
they add up to an amount that you can divide by 3,
then 3 will be a factor of that number
Example: 261 ….. 2 + 6 + 1 = 9 so 3 is a factor of
261.
Divisibility Rules
An even number will always have 2 as
one of its factors.
Anything divisible by 9 is also divisible
by 3.
Fractions
Parts of whole
numbers are called
fractions.
If 8 out of 24
students in a
homeroom were
absent, how much
of the class would
be absent?
How much would be
absent?
8/24 would be
absent.
Another way of
expressing 8/24 is
as 1/3.
8/24 was simplified
by dividing by the
greatest common
factor of 8 and 24
(which is 8).
Math Monster
Don’t be afraid to use math.
The more you use it the
more comfortable it will
seem and the less monsterlike it will become!
Practice using these
concepts!
Hope you enjoyed the
presentation!!