Transcript Parents Guide to Multiplying and Dividing by 10

Parents Guide to
Dividing by 10 & 100
This Power Point Presentation will
Show Parents the Language We Use
When Teaching Children How to Divide
By 10 and 100
Organising numbers:
We organise numbers in columns like
this:
H
T
Hundreds Tens
U
Units
Only a single figure can go into each
column.
Organising numbers:
After working with Thousands, Hundreds, Tens
and Units the children are introduced to
larger numbers
HTh
TTh
Th
H
T
U
Hundreds of
Thousands
Tens of
Thousands
Thousands
Hundreds
Tens
Units
As always, only a single figure can go into each
column.
Organising numbers:
We encourage the children to look at the
numbers in groups of 3 digits.
First look at the:
HTU
Then look at the : HTh TTh Th
HTh
TTh
Th
H
T
U
Hundreds of
Thousands
Tens of
Thousands
Thousands
Hundreds
Tens
Units
Reading Big Numbers
HTh
TTh
Th
H
T
U
Hundreds of
Thousands
Tens of
Thousands
Thousands
Hundreds
Tens
Units
3
5
6
0
0
0
The 3 noughts in the HTU says ‘thousand’
Now read the HTh TTh and Th columns: 356 says ‘three hundred and
fifty six’ this is the number of thousands.
The complete number says:
Three hundred and fifty six thousand.
Reading Big Numbers
HTh
TTh
Th
H
T
U
Hundreds of
Thousands
Tens of
Thousands
Thousands
Hundreds
Tens
Units
1
3
7
0
0
0
Every time we see three zeros in the HTU columns we say ‘thousand.’
For the number above the number of thousands is one hundred and thirty
seven.
So the whole number reads:
One hundred and thirty seven thousand.
Reading Big Numbers
M
HTh
TTh
Th
H
T
U
Millions
Hundreds of
Thousands
Tens of
Thousands
Thousands
Hundreds
Tens
Units
1
0
0
0
0
0
0
After some practice with hundreds of thousands, the children are introduced to
millions.
We point out that to have a million we need one figure plus 6 zeros.
To make the larger numbers we use a space to separate each group of 3
numbers.
1 000 000 one million
2 000 000 two million
Dividing by 10
TTh
Th
H
T
U
t
h
Tens of
Thousands
Thousands
Hundreds
Tens
Units
tenths
hundredths
To divide by ten we move the figures one place to the right to make
the number smaller.
The decimal point never moves.
We read the colums like this:
Hundreds Tens Units Decimal Point tenths hundredths
Dividing by 10
TTh
Th
H
T
U
t
h
Tens of
Thousands
Thousands
Hundreds
Tens
Units
tenths
hundredths
3
2
We say:”There’s one zero in ten so we move one place.”
32 divided by 10 is: 3.2
TTh
Th
H
T
U
t
h
Tens of
Thousands
Thousands
Hundreds
Tens
Units
tenths
hundredths
3
2
Dividing by 10
4
3
2
H
T
U
4 3
2
t h
432 divided by 10 is 43.2
We have moved each digit one place to the right to divide by ten.
We read the answer by saying, ‘forty three point two.’
Another Example
H
6
1
T
U
6
1
t h
61 divided by 10 is 6.1
We have moved each digit one place to the right to divide by ten.
We read the answer by saying, ‘six point one.’
Finding 10%
H
5
7
We use this same method to find 10%.
10% of 57 is 5.7
We read the number as five point seven
T
U
5
7
t h
Dividing by 100
TTh
Th
H
T
U
t
h
Tens of
Thousands
Thousands
Hundreds
Tens
Units
tenths
hundredths
To divide by hundred we move the figures two places to the right to
make the number smaller.
We say, “There are 2 noughts in one hundred so we move 2 places.”
Dividing by 100
2
9
7
H
T
U
2
9
7
t h
This time we move the figures 2 places to the right because there
are 2 noughts in 100.
We read the number as two point nine seven
Multiplying by 10
2
9
7
0
Th H
T
U
2
9
7
t h
This time we move the figures 1 place to the left because
multiplying makes the number bigger.
Notice that a zero needs to be added into the units column as the
movement of the digits has left this column empty.
Multiplying by 100
2
9
7
6
0
HTh TTh Th H
T
U
t h
2
9
7
6
This time we move the figures 2 places to the left because there are
two noughts in 100.
Multiplying & Dividing by
10, 100 & 1000
M HTh TTh Th H
T
U
t h th
The same method is used for multiplying and dividing by 10, 100 & 1000.
We use the amount of noughts in the number to remind us of how
many spaces to move each digit.
Multiplying / Dividing by:
10
Move 1 place
100
Move 2 places
1000
Move 3 places
Remember : the decimal point never moves
Click Below to Return to
Our School Website.
We hope this powerpoint will help you to
work with your child at home.
Please ask in school if you have any
questions regarding our approach to
teaching maths.
http://www.killeanps.com