Transcript No Slide Title

UNIT 1
Multiply and divide any positive integer
up to 10 000 by 10 or 100 and
understand the effect.
Decimals
Multiply & Divide by 10, 100, 1000
Level E
Learning Intention
1. To understand how to multiply
and divide decimal numbers by
10, 100, 1000.
Success Criteria
1. Understand the simple rules to
multiply and divide decimal
numbers.
2. Be able do calculations.
3. To understand the effect.
Sunday, 30 August 2009
DiscoveringTime
The effect of multiplying a number by 10, 100, 1000 & 10000
6
six
6
0
sixty
6
0
0
six hundred
6
0
0
0
six thousand
0
0
0
0
sixty thousand
6x1
6x10
6x100
6x1000
6x10000
6
What is happening ?
The effect of dividing a number by 10, 100, 1000 & 10000
Level E
seven
7
1
7
7
10
0
7
nought point seven
7
100
0
0
7
nought point nought
seven
7
1000
0
nought point nought
nought seven
0
0
7
What is happening ?
Level E
Multiplying a whole number by 10
Example
2 4 6 x 10
thousands
=
2
hundreds
tens
units
2
4
6
x
0
add place holder zero
to the units column
4
6
10
246 x 10 = 2460
all digits move one place to the left
Level E
Multiplying a decimal by 100
Example
629
ten
thousands
=
6
4 x 100
thousands
2
hundreds
tens
6
2
9
4
units
Decimal
point
9
tenths
4
x 100
0
629.4 x 100 = 62940
add place holder
zeros to the units
columns
all digits move two places to the left
Decimals
Multiply & Divide by 10, 100, 1000
Level E
To multiply a decimal number by 10,
Simply move all digits 1 place to the left:
e.g.
2.55 x 10 = 25.5
digits are moved 1 place to left
To multiply a decimal number by 100,
Simply move all digits 2 places to the left:
e.g.
DiscoveringTime
1.02 x 100 = 102.0 digits are moved 2 places to left
Sunday, 30 August 2009
Decimals
Multiply & Divide by 10, 100, 1000
Level E
To multiply a decimal number by 1000,
Simply move all digits 3 places to the left:
e.g.
DiscoveringTime
34.567 x 1000 = 34 567
digits are moved 3 places to left
Sunday, 30 August 2009
Level E
Multiplying a whole number by 100
Example
9 3 5 x 100
ten
thousands
=
9
thousands
3
hundreds
tens
units
9
3
5
x
0
add place holder
zeros to the units &
tens columns
5
0
935 x 100 = 93500
all digits move two places to the left
100
Level E
Multiplying a decimal by 100
Example
43 1 7x 100
ten
thousands
=
4
thousands
3
hundreds
tens
4
3
1
7
units
Decimal
point
1
tenths
7
x 100
0
431.7 x 100 = 43170
add place holder
zeros to the units
columns
all digits move two places to the left
Level E
Dividing a whole number by 10
Example
786
10
hundreds
7
=
tens
8
7
786
units
Decimal
point
6
8
tenths
0
6
10 = 78.6
all digits move one place to the right
10
Level E
Dividing a whole number by 100
Example
786
100
hundreds
7
=
tens
8
units
6
7
786
Decimal
point
tenths
hundredths
0
8
0
6
100 = 7.86
all digits move two places to the right
100
As the following numbers appear multiply them by
10.
As the numbers appear multiply by 100.
Level E
Plenary
Sunday, 30 August 2009